New favorite receiver extension - Sons of Liberty Gun Works Receiver Extension

I have two VLTOR A5 aka AR10 carbine length receiver extensions that I got from Larue. Just picked up a SOLGW A5 extension. Comparing them, the SOLGW receiver extension has 9 positions, drain holes in the last two positions for OTB, and the SOLGW omits the numbering that can be seen on the top of the VLTOR/Larue extensions. Looking at the SOLGW extension with a flashlight, there are no burrs or chips or machining defects of any kind.