Very nice piece. I, too, like how you've kept it simple (practical). Too many AR owners "pimp up" their rifles with so much rediculous pointless accessories in reality adding less to it's actual effectiveness factor (though I suppose more to it's "coolness" factor). The AR was initially designed to be a lightweight rifle. The carbine even more so. It's kind of bad, don't you think, when an AR carbine weighs more than a standard rifle? That's just my opinion on the matter.
I own a Sabre Defence XR subcarbine. Only thing I've have added is a C9 FN rear-grip handle as a foregrip to the handguard and am planning on getting a better (more solid, stable) stock and possibly a decent optical sight eventually. For the meantime I'm going to up my accuracy with conventional sights. The rifle only has a 0.29m (11.5") barrel, so the longest range I'll bother firing it is 200m. Anything at a 100m or closer I can do fine with iron sights.
I love my XR-15CQBR! I've never fired an AR type rifle with such a small barrel, let alone own one. I've fired C7s, C7A1s/A2s, M16A2s/A4s, C8A1s/A2s, and M4A1 (and a couple civilian variants friends owned). So even though it's a greatly familiar weapon system, it's still a new experience.
I'll flash some pics around here soon. Likewise, wouldn't mind seeing the final product of your Bushy with all tac gear assembled (sling, etc).