Waking up from sleep has about a 1/3 chance of success, the other 2/3rds of the time the whole thing just hard-freezes and needs a full reboot, which leads into the two biggest issues I had with it:
1. When booting up on a "dirty" filesystem, there's a prompt to power down or press any key to bypass the integrity check. This has a two minute timeout, which is just a ridiculous amount of time to wait. (Also, pressing buttons doesn't actually seem to work to bypass the integrity check)
2. After a power cycle - regardless of whether the power-down was clean or dirty - you lose everything on the microSD other than the OS itself. All settings, all downloaded themes, all ROMs completely wiped. It's as if it's booting from a recovery partition or something. I tried numerous times (gracefully shutting down via the Start-button menu) and each time, it boots back up all wiped clean. Reimaged and started over from scratch - still the same issue.
The sleep issue seems to be a known thing and newer version will fix this by... removing the ability to sleep (see https://github.com/ROCKNIX/distribution/issues/1609).
Didn't see anything about the "clean" (more like "forcibly-sterilized") slate after power cycling.
Not ready for the big leagues, at least not on the CubeXX.