I just put together a Model 1 Sales C.A.R. 16" complete kit on a CMMG lower.
The sales staff was great. I had the kit 4 business days latter.
All components went together smoothly, no "rework" or fitting was required. Color match to my receiver was execellent.
The stock trigger was heavy at about 10 pounds. I did a trigger job and brought it back to about 6 pounds. Heavy or light, the trigger group has a nice clean break.
I just built it up this week so, haven't had the opportunity to shoot it yet. Manual cycling is flawless, headspace is set A-OK (got the 5.56 Nato chamber). As to the ER Shaw barrel, I've used ER Shaw on other rifles and had no problems, they shoot better that I do!
This is my first AR build for a one off report however, any issues M!S had a few years ago seems to be corrected. I'll make a final judgement after a trip to the range.
Also, they seem to be the most cost effective even thought it is only $10 to $40 or so. That pays the shipping.
Good luck!