I run gentoo on my wandboard for almost two years, never tried anything else. I just followed the "tutorial" on eewiki concerning u-boot, then installed gentoo as usual from a stage3 archive (stage3-armv7a_hardfp) and it "just works". Easier than I expected, in fact.
The board acts as a headless server, I have no experience with X.org; except networking everything seem to work flawlessly.
My current setup is a bit complex (system on external hard drive, lots of containters, etc.), I can't use it to build a sd image. I may be able to create an image from a stage3 archive, though, with no guarantee that the system will boot