I've had good experiences with Bushmaster, and their parts are top quality. While I'll agree that their small/large hole adapter kit is a bit over the top and ended up just machining out an offset bushing myself on a lathe, (one simple part. Not three.) I see where they're coming from on that kit.
My only negative experience with BM is that I requested a replacement front sight base for a Bushmaster National Match 20" heavy barrel that I picked up slightly used and stripped of its sight base. They wouldn't sell me the part because it's a part that requires gunsmithing to properly install, and they don't want to honor a warranty return on a part that was installed incorrectly. So I got the same part from Fulton Armory and yes, I installed it properly, drilling the new holes for the taper pins exactly to match the existing holes in the barrel...I have a milling machine in the garage and know how to align to existing holes.
I don't blame Bushmaster for their policies. They're sensible, from a business perspective.
I will buy from both Fulton and Bushmaster again because they both deliver quality products and both gave good customer service, within the limits of their policies.