The good, the bad, and the frustrating...
I have really enjoyed all of the instances of the Street Fighter series. I will admit the first was an epic failure, but without that epic failure we would not have gotten SFII, SFII: Turbo, the other 5 versions of SFII, SFIII, and the alphas. With that being said, if you also have enjoyed those installations of the game you will in fact enjoy this one as well.
The positives of the game are most if not all of the 'classic' characters are back. You lose some of the alpha translations and even one or two of the third installment. It also adds some deep elements of the game with the new focus attack system, carrying forward the ultimate and super combos from the past games, and also incorporating throws and taunts with button commands instead of proximity like in 2 and 3. The best new function is the multiplayer and ladder matches. This adds so much to the game it is relatively unbelievable. However, be warned there are some REALLY good players out there. And I mean really good... but still, you can play your friends via invite or just wander around the network and find some good people to fight with.
Now onto the bad... and there is some bad here, so prepare yourself. First, the computer is ridiculously cheap on an overall basis once you fight normal or higher. This frustrated even the most avid gamers back in the day in the arcade. Second, the new boss - Seth... is as bad if not worse than Bison in the original. He's not impossible, but if you get him low on life get ready for the cheapest barrage of attacks you have ever seen. Also, I'm not quite sure I get some of the priorities and animation glitches in the game. While you can learn them and exploit them against the computer and online, I find it to be very unintuitive and frustrating at times (especially playing people online who know them and know them well). I guess that bridges into my last comment... when you play online, unless you play at non-peak times you encounter the "world's best" or at least most of the top 10% of the world. Much like in any online game, this is no arena to learn. This is where you come to get destroyed by people who have logges several hundred hours and in fact have it blocked off on their daily calendars to play this game. They are amazing to watch, frustrating to play, but overall they are good sports and will even offer advice via bluetooth.
Either way you look at the game... it should be picked up if you are a fan. I hesitate to put new SF players onto the game because there is a horrific learning curve of most deep fighting games. However, if you are a fan or an avid fighting game fan... this needs to be in your library. I recommend the Collector's Edition... it has some good content and comes with a movie which bridges the series together. Gives you a much deeper knowledge of the series and the characters' backgrounds. Good luck, and maybe I'll see you online for a few matches ;)