Just got mine and am installing it now. I'll be the guinea and let y'all know if it explodes.
edit: It seemed to have worked, my laptop didn't spontaneously combust. It only took about 10 minutes to install. The display preferences have the same options for Retina, or changing resolutions. Other than that, I'll have to experiment a little. Cheers!
So it solved all the performance issues for you?
I installed DP4 on my rMBP yesterday. Generally speaking, the UI performance is indeed a lot better than Lion. However, scrolling in Safari is still very laggy on most websites, especially Facebook.
Anyone else with DP4 experiencing the same problem with Safari?