3870x2 runs smooth at 1920x1200 without any forced AA. However the one review i saw on performance would indicate a gx2 and a X2 were slower than their single card counterparts, so sli/crossfire wasn't working when the review was done a couple weeks ago. Basically runs pretty damn sweet on a 3870/8800gt and will probably get faster with crossfire/sli with new drivers.
It is a touch repetitive, not sure if its any "more" repetitive than any other games, its a lot longer than say COD4, had it been the same length it wouldn't have gotten repetitive.
honestly you can see where the design time went, the cities are pretty huge and I've yet to come across any places you can't get to. Theres an immense array of buildings, styles, designs, and variable routes everywhere. Its a shame, i don't know, there isn't a little more story to it and some more stuff to do. Didn't use the short blade in a multiple enemy fight for ages which was quite cool to play around with, some cool killing animations there. Animation is great aswell, very smooth.
Well worth buying anyway, its a shame that i think lack of story and reasoning really but the design of the cities and the idea is great and they've gotten those parts basically perfect, you want games like this with increased level of detail and more open play then you need to support the studio's who put time into making the games
If they do really well, next game will hopefully be more of the same plus improve in the area's we weren't happy with. Don't buy them, they won't be bothered to improve it and will release a quick crap story shoddy sequel to cash in on the name.