I have done both...did IMCDA course in 2006 so I know they have changed it. They are similar I think (Both rolling), the difference between the two really being the weather. Even tho it was hot the year I did CDA (in the 90s) it was low humidity.

I did CDA last year and LOU in 2010. Very different bike courses. LOU as you know is mostly rollers throughout, with 1 climb of any note. CDA's climbing comes from a ~2 mile climb done twice and then a 10 mile section out to the turnaround that climbs steadily the whole way. Its slow on the way out and fast on the way back. The course consists of 2 out and backs to town done twice, so spectators can see you on the bike 4 times from the hot corner. My file puts the climbing for CDA at ~5500ft.