I run CTR's on both of my SBR's. I liked the CTR so much that I replaced all of my stocks with CTR's.
I read Jeff's post a while back when the UBR was first coming to market and I was fortunate to snatch one up and it sat in a box.
I finally picked up a BCM mid-length and slapped in on one of my spare lowers and just didn't like how it balanced. I then remembered the UBR I had and slapped it on my lower and it was a HUGE difference in feel.
I still use the CTR's for 14.5 and shorter barrels, but the UBR is king of the midlengths. I like the SOPMOD for a 16" carbines, but not so much more than the CTR to justify the price difference.
My patrol rifle is a BCM Mid-length on a Noveske lower, UBR stock, Aimpoint ML3 in a Larue mount, a FUG, 6P LED in a in-line Larue mount, and a BFG Vickers sling. This setup balances really well and I can carry it for long periods of time.

