Played both versions. Played one where I did all good, one all bad, and then one where I made decisions that seemed more realistic. The last one was pretty much I did all good except I tried to save Trish and I became Infamous at the end. Good is more fun though because the powers are more interesting. Bad simply gives you more destructive power. Also, the bad missions creep me out. I'd rather be a super hero then some punk with powers.
Have not gotten the second one yet, but I plan on it. I'm very tempted to buy it now but there is a slim chance that I'll wait for a while until the price goes down (A VERY slim chance). I am a huge Infamous fan. I've always loved superheroes and the ability to play as one is always epic in my eyes. But what really won me over was the complexity and depth of the story. The plot twist at the end had me standing on my feet in awe, and after that I went back and found all the little twists. Paying attention the second time around really made me appreciate it more.