Back when I was in the AR market years ago it seemed that most everyone considered BCM products to be top notch. I'm sure there were some who felt otherwise.
Anyway, can one go wrong by purchasing a new BCM in 2020 or has the quality of their products slipped?
Big Daddy Unlimited has BCM parts, lowers halves and complete rifles, but no complete uppers. Since they are a discount warehouse membership service, pricies are typically very good.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
II'm pleasantly impressed with my BCM 11.5" pistol. Bought the upper and lower separate to save a little $$. Before any adjustment, With an Aimpoint H2 and American Defense mount on top, it shot a group the size of a golf ball 2 inches right of bull with Black Hills and IMI 77 gr BTHP. And I don't see that good any more.
Slaves get what they need. Free men get what they want.
I don't know how to rate the quality. other than to say it's clearly serviceable. I believe It would take inspection by a top notch AR 'smith to really go through one and quantify the precision of everything. I just know they seem to have a fairly good reputation for their price.
Here's my only example, it's a BCM M4 SOCOM 14.5" upper. I added Troy quad-rail handguards, and built the lower from a stripped PSA. Topped-off with a Primary Arms 5X prism, and a Cloud Defensive OWL. Loaded up with Magtech 77gr OTM. One of my favorite rigs. Typical AR accuracy.
BCM's stuff is generally well above average, depending on what you are trying to accomplish.
But for a "precision" rifle, I'll look elsewhere for barrels & handguards; having said that, I like their receivers, BCG's & their handguards feel great in the hand, but the mounting system for the rails, & the rails themselves leave a little to be desired on rigidity for a "precision" rifle. (I'm referring to their free-float stuff)