Yes the port is rubbish and glitches annoying, but if you are willing to look past that then it's great fun.
I got my copy on steam and ran into problems immediately on Win7. Every time I tried to start the game it would CTD, a quick google and I discovered this was a problem with the default graphics settings or lack of. Downloading a config file that booted it into windowed mode fixed the issue and I was able to set it to whatever I wanted after that and never had a problem since.
The optimization/port of this game is obviously bad, especially for me who came from SR3 and was used to decent graphics, suddenly having GTA SA level of graphics but worse FPS then SR3 was a shock. I use a tool called "dxtory" to cap my framerate, which helps but while cruising around town you can expect your framerate to be dropping below 25fps frequently.
Lastly on the optimization, the game does crash occasionally. Maybe once every 2 hours or so of gameplay (this is on the latest patch), but you can save as many times as you want and don't have to start deleting old saves to free up slots like SR3 (WHY!!?!? - I have a 2TB hard drive!!!!)
I suspect most people would have gotten the hump at this stage and just given up but I was determined to give SR2 a shot since I had heard good things on the forums, about how SR2 was better than SR3 in a lot of respects. After having played SR2 for a while now I definitely agree with them but I didn't initially think that, it's a grower for sure.
The style of the gameplay between SR2 and SR3 is significantly different, in SR3 they obviously went for a more wacky in your face insane approach where as SR2 is not as absurd and has a darker more brutal theme to it in some of the missions. That being said there is still a tonne of laughs to be had and I definitely found this game much more fun on my second playthrough (as an aussie dude). On my subsequent playthroughs I really took my time and tried to experience all the side missions and found it immensely funny and entertaining; like I said SR3 relies on being wacky and in your face comedy while SR2 is more subtle but I think SR2 is ultimately much more entertaining than SR3.
The gunplay is also imo much better in SR2 than in SR3; the enemies don't take as many hits to die, which annoyed me in SR3 where they keep spinning around and sucking up tonnes of bullets. The guns feel and sound better, especially some of my favorites AR-40 (m16), AR-50 with nade launcher (XM8) and the AR-250 SAW.
The story and characters are way better in SR2; you have 3 (technically 4) gangs you have to deal with in Stillwater, each of which are unique, have their own style and can be dealt with in any order at your own whims. In SR2 you get to meet Gat, who is a great character and brings a lot of comedy moments, plus you have Pierce and Shaundi, both of which are significantly different from their SR3 counterparts, especially Shaundi who is almost unrecognizable in almost every way apart from being a woman obviously.
Graphics are pretty bad given the game released in the same year as GTA4 but to be honest I could care less, i'm not a child. Yes it would be nice to have SR3 graphics in SR2 but the gameplay MORE than makes up for it.
The driving is straight up bad; you need to get this aspect modded immediately and even then they aren't great. I have done quite a bit of my own personal modding on this aspect and also bought a controller specifically for this game which helps a lot. This is probably one of the worst aspects of the game, aside from the optimization woes.
In response to that the customization of the character is way better in SR2 than SR3. Instead of having pre-made sets of like a coat and shirt like in SR3, you can pick the layers individually and there are a better selection of hairs imo. Facial hair in this game is actually hair and not just a painted on texture like SR3. Not to mention that you can customize your characters fighting style, walk style and a bunch of other stuff that SR3 should have had and I don't know why they didn't (laziness?).
Overall I have had and am still having a lot of fun with this game. Yes the optimization and poor graphics are annoying but if you're not a fool and can actually see past that stuff then there is a real gem of a game here not to be missed.