I'm always looking out for a nice single board computer (SBC), but my phase when I looked at all those (on paper) nice sounding SBCs through rose-tinted glasses is long gone, the only question I want to have answered when checking one out now is:

Does it have Linux kernel support in the mainline? I.e., not some weird semi-proprietary patch blob on some GitHub account basing of the 3.18 kernel or so..

If it doesn't, I can close the tab immediately and know for sure that I won't miss out. If it posted patches to the LKML, maybe even in an advanced revision integrating review comments then it might be worth looking at it later.