I had the day off yesterday, so I spent a fairly ridiculous amount of time on Rome II (let's just say I racked up about 15-20 achievements). It's a pretty great game, but has some of the same basic problems that all the Total War games have had (not that I'm knocking the series - I'm a huge fan). So far my impressions are as follows:
The Good -
The sheer scale of the game is staggering. They've been advertising this game as by far the largest map that they've ever made, and they do not lie. Moreover, there's a metric ****ton of units, individualized tech trees depending on cultural background, etc, etc. This game is huge, and I imagine - more so than (e.g.) Shogun - playing as (say) Egypt will be a totally different experience from playing (say) Rome.
Graphically it's gorgeous. I actually recently bought a custom gaming desktop, so I've been running Rome II on the highest graphics settings, and the detail is fantastic. I especially love the effort they've put into varying the regions (both on and off the battlefield). Fighting (or moving around) in Egypt looks and feels totally different from sacking some crappy village in central Europe.
There seems to be a lot more variation in general in battle type/layout. I have yet to see the same town map used during an assault, and apparently (though I've not seen this yet) a few of the larger cities (e.g. Rome, Carthage, Athens) have custom maps of their own.
As they've done with every previous Total War game, this one's just a little bit better, more streamlined, and more intuitive than its predecessors. The changes they've made to the interface (especially the army cap) make for a much more efficient and less micro-managingly laborious experience, especially when you've started to accumulate some territories/provinces.
The Bad -
The new internal politics system doesn't seem to matter all that much. Granted I haven't played through an entire game yet (I'm guessing the full campaign takes several days - I played a LOT yesterday, and I only have about 15 territories so far playing the Romans), but so far I haven't seen politics impact the game in any but the most cosmetic of ways.
Diplomacy still sucks for the most part. Yes, they added specific numerical cues so you know exactly why everyone hates you, but still, getting even basic agreements out of people is essentially a matter of bribing them. This game is clearly better than it's predecessors on the diplomacy front, but it's still a Total War game, so diplomacy is still frustrating and fraught with random insanity from time to time.
I've noticed the usual weird AI glitches have not been entirely disposed of. This isn't a big deal, but it is occasionally annoying. For instance, I was defending a land/sea town assault yesterday. For the most part, my enemies moved their boats up to the coastline, disembarked, and proceeded to get murdered by my troops, but a couple of the boats just sat there at the coast, totally full of soldiers. Even worse, one of the boats almost entirely unloaded, but the last two troops couldn't figure out how to get off the damn boat, so the entire unit just milled around - untouchable by my troops, because the computer didn't recognize the unit as being on the ground yet - for the entire duration of the battle. I had to sit in fast forward mode for like a half an hour while everyone stood around looking at each other. It was annoying.
Conquering all the territories of an opponent does not instantly destroy any remaining armies and navies it might have. This means that after you've wiped someone out, their stupid little remainder armies will repeatedly try to take your cities. This isn't really a problem (strategically), but it's annoying to have to auto-resolve a bunch of tiny little crappy battles all the time. This was exactly the problem the army cap was meant to fix. For the most part, it's successful, but not so much in this one area.
But overall, I'm just being nitpicky. This game is excellent, and its clear that the Total War team just gets smarter and pushes itself harder with each iteration. Rome II does not disappoint. I imagine I'll be playing it pretty obsessively for the next several months.