Turks:

Turcomen Foot Soldiers- Really bad attack, but have decent armor and defense, as well as being fleet of foot. Additionally, IIRC, they can be trained from one of those Turkish provinces with +1 valor as well. Far superior to regular archers, but still kinda meh.

Futuwwa- Very good attack, sorta bad defense. Great for shooting and flanking, but care must be taken when handling them, as they can die pretty fast. They do have a large shield, though, which aids in missile duels and survivability.

Ottoman Infantry- +1 valor in Rum. Pretty good attack, okay defence and armor, good morale, and (very unusual for a ranged unit) an armor piercing melee attack as well. Get a master bowyer in Rum and these guys are high quality units all around.

Jannisary Archers- Okay. Okay attack. Okay defense. Okay morale. Okay armor. Nothing really special about these guys, and, imo, they are quite obsolete for the Turks. Hence why I usually mod them to have longbows so that they can actually serve a purpose.

Jannisary Infantry- Jannisary Archers who can do so much more. Better attack, better defense, and slightly better morale. However, they are also kinda obsolete by the Ottoman infantry, because these guys can't pierce armor. Hence, I tend to mod their defense up a point or two so that they truly serve their purpose, and are deserving of their incredibly high requirements(Master bowyers, swordsmith guild, military acadamy). Again, I tend to mod the requirements for the Acadamy so that it isn't dependant on a grand mosque/Cathedral, but that's just me.

Turcomen Horse Archers- Pretty decent horse archers. Can be trained with +1 valor from Antioch, and with a master horse breeder, they will be quite capable as a light/medium cavalry in combat, as long as you don't send them in headlong into other charging units.

Sipahi of the Porte- Royal unit in the late period. Personally, I'd rather have late Ghulam Bodyguards. The bows simply don't do enough damage with a 20 man unit, and meanwhile, it decreases the units charge capabilities. Plus, many late period units are armored quite well, and thus arrows don't even do a lot against most of them. Thus, I mod them to be a 40 man unit, sorta like a somewhat superior Boyar.

Anyways, I think that about sums it up.