Just started riding last June and have a compact 50/34 on my Madone w/DA. Since I live next to the Sierras, I tried the IRD with 34 cog with my DA rear derailer. No way it would work without rubbing and the possibility of a lock-up if one goofed and used the front 50 with either of the biggest rear cogs.

I'm now using a SRAM 11-28. The 28 does make just a little bit of noise with the the rear derailer, but it works fine.