Now let me say, I already have Street Fighter 4 and really did not like it. I played it for about a week and was so bad at it and just got too frustrated with it to enjoy it. 
 
So why then, would I buy Super Street Fighter 4? 
 
The answer is simple. All of the characters are unlocked.  
 
Now this may seem trivial to many people, but that is one of the reasons I became so frustrated with the original SF4. I was so bad at the game that I had a lot of trouble beating the Arcade, even on the lower difficulties. I became driven as a completionist to first unlock all of the characters before I could enjoy the game. Unfortunately due to how bad I was, I couldn't unlock most of the characters and got tired of the game before I could really enjoy it, or get good enough to unlock them. 
 
Now with SSF4, I can still barely beat the arcade, but now I feel that I don't have to, and I'm not failing any sort of mission I have. I can just mess around with all of the characters, trying to get better without having to worry about unlocking people. 
 
Having the game for a day now, I'm already enjoying it a lot more than I ever did SF4 and I foresee myself continuing to enjoy this in a way I never could with the original. 

 So often with games I tend to get hung up on trying to complete all of the little things and too often this tendency interferes with the game experience as a whole. I never even complete games in their entirety, and yet as I go through them I'm always focused on not missing anything. If there is ever an item you can miss getting, I always jump through any hoops to get it just because I can't stand the idea of having my game not be able to be complete, even if I will never actually complete it. 
 
The problem with this is it really gets in the way of the play too much. In Fallout 3, for example, every time I did a quest I would go look up all the possible outcomes and made sure I got the best one. Even though I never even hit the level cap or got close to completing all the quests, I just couldn't let little things by and that is eventually what caused me to grow tired of the game - I couldn't just play however I wanted.