@ReaperX7, I think I've seen you on the LFS forum so telling you that it will do from start of CLFS to the end of "Constructing a Temporary System" in about 3 hours should give you an idea of performance. Quad core, out-of-order processor and DDR3, it's quite nippy
That's with a SSD connected via USB, but that's also with it de-clocked to 1.6GHz.
Yes, it does have power issues, many run the 5v supply directly onto the pins rather than via the inadequate micro-USB. De-clocking was my "temporary" solution I haven't got round to fixing yet!
Slackwarearm-current and the 4.12.0-rc5 run stable here - and that's with it flat out doing compiles - run headless so I can't speak for the graphics/audio side. The only niggle I can report is that if I try and run distcc for those compiles they stall, I haven't had a chance to look into anything recently - is it again power related? Remove distcc and it works fine.
In terms of support - well, like you I was expecting something really good from Asus, instead, it shipped with a "dirty" kernel, uncommitted changes in release software, really? Sadly Rockchip don't seem to have "got" the Gregg-KH message, so don't expect them to be pushing stuff into mainline.
That said, others have picked up the problems, mainline kernel and uboot work and I believe the not-rebooting (needing a power-down instead) is fixed in 4.14.
Time for me to go find out
Edit - not yet working here