I've just got the Strategy Guide and spent an hour skimming over it.

It is VERY good for the unit stats - if you want to see the numbers, compare troop types etc, it is nicely done. Quite comparable to MTW; maybe a little better (gives overall defence as well as component factors of armour, shield and skill; includes a missile "attack" stat). This is probably the main function of the guide for me. It does miss information on morale and unit speed (e.g. are cats slow?) though. This unit information is bloated by stuff on buildings which would be better represented by a pull-out tech tree as came with MTW.

For everything else, I am not so sure. Certainly no quantitative information on combat formulae, unlike the STW and MTW guides.

I can't see much - anything - on faction specific campaign strategy tips. These were short in the STW and MTW guides, but very appreciated by me. This absence is a very big shortcoming.

A big disappointment is the "campaign map". It is advertised as fully detailed - indeed this is the big selling point on the back of the book - but I can't find it. There is a blurry, small thing on p187, but you can't make out many province names let along cities or other detail. p179 has a much better sized photo, but it covers only Gaul and a bit of surrounding provinces. Very annoying.

There is a fair amount on the historical battles, but these are of no interest to me.

Bottomline: buy it only if you want a handy way to access unit stats, to find out the best unit (Answer: Praetorians!, esp. the urban cohort ones)