Love the improved feats, but dislike the new backgrounds.
Backgrounds are a Trap Mechanic now. It will restrict players who want to optimize their character (Attribute Choice and Feat), while those who don't care about mechanics (like new players) might choose backgrounds where their Attributes and Feat is useless.
So it's Mechanics vs. Roleplaying, except if you are one of the lucky few where your Character Idea has a good class and background combo. This would not have been a problem with custom backgrounds, which you can do now .. if your gm lets you do it (this will not be a pleasent discussion on some tables).
Also I miss the personality traits. The players loved rolling them (or choosing an interesting item) which usually enrichted their characters, especially with new players. It's not a big deal, you can simply make your own or use old background tables, but it would have been helpfull if the backgrounds would have included them.