At least for me, 4th is much simpler although character creation is more limiting. Part of the goal with 4e was to streamline 3.5, and they more or less gutted 90% of it in the process. I did enjoy 3.5, it's just that 4e was much easier to get into for a game. Character creation, while still a bit difficult for someone as easily distractable as me, was much easier in 4e than 3.5 mostly due to all the information being readily available whereas in 3.5 you have to go on a manhunt just to determine your armor class. Gameplay is mostly similar, with the only difference I personally noticed between them being attacks of opportunity. Where the biggest difference by far is is the roleplaying. Unfortunately, 4e seems to have done everything it can to elminate roleplaying for the game. Most skills do very little in combat, and have only minor effects out of combat. The makers seemed to have forgotten that there was once more to D&D than killing shit. While you can still roleplay freely, there is little mechanical support for it.