I've played Mountaintop, Colorado GC, and Irish Creek. The comments here about Colorado GC and Irish Creek are dead on. Irish Creek was I believe a renovation of some holes, mostly the front nine, and then mostly new holes on the back. The final six on the back are very good, and the earlier holes along the river are fine as well.
Colorado CC had a number of excellent holes as well and overall I thought the course deserving of mention as a top new course. At the same time, I had the perception that there was a bit more earth moved to build this course than other C&C courses I've played (Cuscowilla and Chechessee), that the course was more built than found.
Mountaintop was definitely my favorite new course this year, and earlier I've posted very complimentary comments on this site about the course. We played Mountaintop and Wade Hampton on the same day, and I thought Mountaintop the stronger, more difficult golf course tee to green, although I thought WH's greens could be more dangerous. MT's mountain views were spectacular as well, especially from some of the holes on the back nine. WH is wonderful, and I believe deserving of its high standing, but I think that if both courses opened on the same day and neither had any history, MT could very well be the course that got most of the buzz.