I'm currently about 40% into Batman: AA, and I'm very interested in Mafia II. Both of these titles use PhysX, especially Mafia II. There's a review on Mafia II floating around somewhere where the reviewer stated that he didn't enjoy Mafia II as much without PhysX. As a matter of fact, he stated that it took the game from good to great for him.
What's everyone's opinion on this? Should I do it?
Really, it's entirely up to you, but from what I've seen I can say that PhysX don't add THAT much to a game. It's a nice feature, but in the end it's not like you loose all kinds of actuall detail by not having it. (Really the biggest thing you'll loose is frame-rate). The most i've ever seen PhysX used for is little chunks of concrete or glass flying off in Mafia 2, or papers in Batman. Honestly, i don't see how something like that could make or break a game, i recommend playing the mafia 2 demo and see for yourself. PhysX is also a frame rate buster, so that's something to think about.
Also, you'll a lot of heated opinions Ranging from "Sucks" to "Best thing ever", so be warned, it might get hot and heavy up in here. Just remember that it's your choice and you can do whatever you want. It might be worth it to go searching for youtube videos that show what PhysX adds to Mafia 2 and Batman. It also might be a good idea to look up what kind of FPS those people are getting.
Not worth it! I am a nvidia user and physx is only a perk not something that one should make a priority. If you need it that badly then go multy card with hacked drivers. Have some common sense that 5870 is a better card and doesn't run like a blast furnace ffs.
I have been down this road and only a few games take advantage of physx. If you are that desperate then get a cheap GT240 or a used 9600/9800gt and memory size isn't important. physx only needs 256mb to work and is bandwidth hungry. Third nuke the shader that does the trick. Don't bother with the core as it does not improve physx performance. Also you will need to hack the drivers (nvidia) for multy card but hacks are easy to find if you know ware to look. I really liked the sli hack.