I've been running a number (3, with 1 spare) J1900 Brix units. I think mine came with F6 BIOS. Flash to F7, installed Win7 64-bit SP1 on the first half of my Intel 320 Series 300GB SSD, and then messed with various Linux distros in the other half of the SSD. Finally, once the F8 (Win10 fix) BIOS was released, I flashed that F8 BIOS, and then disabled "C state reporting to OS" in the BIOS, and installed Linux Mint 17.3 Mate 64-bit, and now it doesn't freeze anymore when booted to Linux, and reboots from Linux properly. (Used to have to force power-off when rebooting from Linux.)
Using an 8GB DDR3L-1600 SO-DIMM from GSkill, the CAS9 version, not the CAS11 version, I think.