I just got this game through the post this morning and have been playing it for about an hour now. It runs fine (40 - 60 fps) with everything maxed at 1920x1200 and 8xAA on my system and the ridiculous (IMO) DRM is so far proving to be unintrusive (although that's only because my internet connection is behaving itself at the moment, which doesn't always happen...). So far so good.
When I first loaded the game though I was initially confused as to why my Xbox 360 controller wasn't being recognised so I checked the ReadMe file to see that it is supported (it is). It seems you have to turn it on BEFORE you load the game then select it from the Control option. Anyway, upon playing the game with the Xbox 360 controller I noticed that the default button mappings were wrong or, rather, not what I expected them to be.
For starters, the right analogue stick doesn't control the camera at all, you have to use the triggers (RT and LT) which means you cannot look up or down!!! Secondly, the four face buttons, despite being colour-coded to (presumably) the 360 controller, don't actually match the specific buttons as Y and B seem to be swapped. Finally, the game kept pausing to the Map screen because I was accidentally hitting a button I shouldn't have been while fighting. As you can imagine that was annoying (I get thinking it was because of the DRM to be honest).
So I decided to reconfigure them so they matched the 360 version (why didn't they do this by default?). I've managed to get a better control setup but unfortunately in mapping the right-analogue stick it means that the triggers, RT and LT, cannot be used at all as they aren't recognised. This is the exact same issue the first game had so you'd have thought that Ubi Soft would have sorted this out by now. The Xbox 360 controller has been widely supported by many games for a good few years now and they all allow the use of the triggers.
And while I'm griping, why can't Ubi Soft show the correct Xbox 360 buttons like the 360 version for this controller? It must be pretty much a standard controller for PCs these days and it shouldn't take too much effort to use both the 360 default control mappings and the button icons themselves. It's all very well claiming in the ReadMe file that this game supports the Xbox 360 controller but evidently no-one thought to actually check to see if the default mappings were usuable!!!
I'm using the latest v1.2 64-bit drivers for this controller by the way and I'm using the wireless controller.
I always thought the wired and wireless controllers used the same drivers though, it's only the way they're connected to the computer that is different.
I'm wondering if it might be worthwhile picking up a wired 360 controller if this is the case as UbiSoft never fixed this issue in AC1 so I doubt they will for AC2 either.
I'm currently playing the game without the First Person Camera (not that useful anyway) or the Centre Camera (not really needed if you use the right-analogue stick for camera control). It's a nuisance not having all of the controls but I suppose I could manage with the mappings I have now.