Here's my tiny, 12 liter gaming pc built for traveling-- recently, if I need to travel to my couch. Small computers are great because I won't accidently exercise from picking them up. At first, I felt guilty for spending extra money for a smaller computer, but, when I found the sffpc reddit, I Immediately felt better about myself... and extremely jealous.
The build
Cable management is a breeze -- it only took a minute to stuff it all in and screw the panels on.
As long as the intakes are not against a surface, the thermals are fine. Around 65c for the CPU (i5-6400) and 75c for the GPU (rx480 3fans). The GPU seems to exhaust into the back of the case, so a blower style GPU might perform better, but I haven't tested that.