Ok, I'll fess up, I helped him order/build this (slash built most of it for him). Will answer a couple of questions for him too, since he is a n00b to ARs and might not know the answers to all.
It shoots amazingly. Sights are zeroed. He needs to get it somewhere to let the legs stretch out a distance on it though.
Its and 18" rainier match, 223 wylde barrel. He wants to take it to 500-600yds, so he will likely want/benefit from an optic.
Its mid-length. We built the lower while he was waiting on upper parts. The upper parts came in and he hand fitted together to get the pic, with no gas block. That was an inside joke giving him a ribbing for posting that pic when he can take a pic of it completed now.
Yessir.