New unit at the .COM - Trebizond Archer

[anti_strunt]

A long kontos spear, used two-handed, was pretty much the norm for armoured shock cavalry in the Middle East for a long, long time. Often accompanied by a shield strapped to the left arm. It didn't give quite the same impact power as the couched lance, but on the other hand remained way more useful in the ensuing melee and eventually actually long outlived the one-handed couched-lance technique; light cavalry lancers were still employing a variation in the mid-1800s.

Such long two-handed spears were actually something of an international norm across Eurasia - even the Japanese started using them eventually.

'Course, a shorter one-handed spear worked right well too and was even more common.

All true enough I suppose, although with little bearing on the cataphracts, since the two-handed kontos had fallen out of use centuries before the start of MTW2 in favor of the one-handed kontarion, which was light enough to be thrown. The page you kindly linked to shows it quite well:
http://www.levantia.com.au/military/kataphraktos.html
The use of a two-handed lance in combination with that kite-shield (quite probably adopted from the Franks) would've been rather impractical.

Plus if the way Alexios Komnenos reputedly survived that one defeat against the Normans is real, top-of-the-line Kata harness was actually pretty damn near lance-proof...

If you are talking about the following lines of the Alexiad:

Amicetas missed the Emperor because his horse swerved a little; the second man's spear the Emperor thrust aside with his sword and then bracing his arm, struck him on the collarbone and severed his arm from his body. Then the third aimed straight at his face, but Alexius being of firm and steadfast mind was not wholly dismayed, but with his quick wit grasped in the flash of an instant the thing to do, and when he saw the blow coming, threw himself backwards on to his horse's tail. Thus the point of the spear only grazed the skin of his face a little and then, hitting against the rim of the helmet, tore the strap under the chin which held it on and knocked it to the ground. After this the Frank rode past the man he thought he had hurled from his horse, but the latter quickly pulled himself up again in his saddle and sat there calmly without having lost a single weapon.

I don't know how you can draw any conclusion about the impervious nature of his armour, since he was not actually struck!

[Moved stuff up here]

A lot, since he (and one would assume his bodyguard) wore a harness essentially identical to the standard cata equipement; full mail over which went the rather formidable klibanion (an improved Byzantine variation of the standard lamellar corselet), plus all the usual limb defenses and padding underneath.

That's more or less the standard equipement of elite armoured cavalry in most of Eurasia since Antiquity anyway, actually. Throw in horse bard. Muslim heavy elites employed similar schemes, and for example the Mongol elite heavies differed mainly in lacking the mail hauberk underneath and relying mainly on lamellar (often of leather; nomads tended to have trouble getting their mitts one enough iron).

Actually, if I remember correctly, the kataphractoi usually rode horses protected by leather and felt, rather than full metal bards like their 5th century predecessors. Regardless, I'm quite sure that the armour was of excellent quality. However, how does it compare with Frankish mail? Let's hear what Anna has to say about it:

...and the order of battle in which they were to arrange their men for the fight. Most of them were to make an attack on horseback and then ride back again, and to do this repeatedly and use their bows and arrows; the soldiers carrying spears were to advance at slow march behind them, so that if by chance the archers were forced back too far, these soldiers could receive them and also strike at any Franks that came to blows with them. He furnished them abundantly with arrows and exhorted them not to use them sparingly, but to shoot at the horses rather than at the Franks. For he knew that the Franks were difficult to wound, or rather, practically invulnerable, thanks to their breastplates and coats of mail. Therefore he considered shooting at them useless and quite senseless. For the Frankish weapon of defence is this coat of mail, ring plaited into ring, and the iron fabric is such excellent iron that it repels arrows and keeps the wearer's skin unhurt. An additional weapon of defence is a shield which is not round, but a long shield, very broad at the top and running out to a point, hollowed out slightly inside, but externally smooth and gleaming with a brilliant boss of molten brass. Consequently any arrow, be it Scythian or Persian, or even discharged by the arms of a giant, would glint off such a shield and hark back to the sender. For this reason, as he was cognizant both of Frankish armour and our archery, the Emperor advised our men to attack the horses chiefly and 'wing' them with their arrows so that when the Franks had dismounted, they [342] could easily be captured. For a Frank on horseback is invincible, and would even make a hole in the walls of Babylon, but directly he gets off his horse, anyone who likes can make sport of him.

So, as formidable as top-of-the-line Byzantine armour might have been, the Franks were hardly very far behind; at least if the Emperor is to be believed... Very interesting link, anyway, I have the greatest respect for the knowledge of reenactors and others involved in equipmental study, but they rarely give you a complete picture; it's rather like trying to analyse the German army of WW2 by replicating a Karabiner 98k; there is a multitude of different historical and archaeological sources to consider. Nevertheless, they are, of course, of supreme usefulness when deciding matters of equipment.

The Muslims learned the tactical peculiarities of the "Frankish" massed couched-lance charge rather quickly, the same way the "Franks" living in the Outrémer were pretty quick to adapt to the peculiarities of Muslim battlefield tactics. The Byzantines were obviously no dumber. The thing was that neither adopted the technique, generally preferring a less all-out and more coordinated approach to shock cavalry tactics; the sheer shock power of the "Frankish" technique was however well respected, and whenever possible considerable effort went into eliminating it through the use of terrain, archery, light cavalry screens and whatever. Often, however, it was found necessary to simple meet it head on with friendly heavy cavalry; after they'd gotten over their initial surprise the Easterners proved quite capable of standing up to it if needed, although they preferred to avoid doing it if possible.

That "less all-out" of course made all the difference, as impetuousity works to your advantage in a head-on charge (unless you are fighting against horse archers or similar light enemy, of course); if two units of cavalry are equal in everything else, then the unit with the most ferocity and drive will win. Not going "all out" is not conductive to this, which is why muslim cavalry lacked the penetrative power of western knights, and probably why Manuel I reformed his native cavalry (the majority of which had never been heavy, charging cataphracts) to charge in the Frankish fashion.

Of course, this on the other hand gave muslim cavalry the benefit of much greater tactical mobility; and most crusader defeats (such at Hattin) were the result of the muslims using their mobility and greater numbers to good effect. But when crusading knights actually did come to grips with their foes on somewhat equal terms, they usually they usually prevailed; such as at Montgisard or Arsuf, where in both battles they broke through Saladin's personal mameluke bodyguard, which would presumably be the best cavalry in his army, and thus somewhat indicative of muslim heavy cavalry in general. Even at La Forbie (1244) the crusaders were forcing back Baibar's elite mamluks when they were surrounded and crushed by the Khwarizimians...

The Ottomans were always eager to employ Serbian knights because those were, you know, in Serbia and thus readily available for combat duty on that theatre, unlike for example the elite kapikulu sipahi heavy cavalry that went with the Sultan and hence normally resided in the capital, or the Anatolian troops who had to be called up from Anatolia. Not that they were ever adverse to employing local troops anyway, especially on far-flung fronts. Remember that campaigning across the Balkans stretched even the formidable Ottoman organizational and logistical chutzpah to its limits - Vienna is actually closer to Paris than Istanbul (the main assembly and supply area of the Ottoman army), and that's not yet counting the difficult terrain of the Balkans along the way...

Yet they still thought it worthwhile to bring some 20.000 serbs (mostly heavy cavalry) along to fight Timur at Ankara in the middle of Anatolia? Where they were they only ones to break through the Timurid lines, including smashing his elite cavalry some three times and only leaving the field after the rest of the Ottoman army had broken?