To add in on what people said on his mic-work, I wanna say that it has definitely improved but that it's also hard to take him seriously at times. You see him corpsing more often than not and he just has this wackyness about him that just keeps me from taking his promos seriously. Also, sometimes he needs to get to the point a bit faster in my opinion. I think early 2012 he was at the peak with his mic-skills, but I'm thinking that is because the gimmick suited his mic-work better. It was a good mix between his humor and making a point. However, he cut his best promo I've seen post SummerSlam on RAW when he was straight shooting at Cena.
EDIT: Didn't realize this thread was so old, lol.