I guess I'm coming from a weird place in that 4th edition was the first time that I seriously played D&D. I played 3rd edition a few times with my brothers group back in high school when I was living at home and I thought that it was a really complicated set of rules that didn't really give you anything for the extra complexity.
(Possibly, like most complicated things, it allowed people who were willing to really dig into it and learn the ins and outs to do amazing things. But for a social game I would see that as almost a drawback; newbies who didn't know what they were doing would get to sit there thinking "Wow, Janna's character can do all this cool stuff but I can't. This game sucks.")