I own both, and have buddies (that's "buddies" plural, as in more than one, not just one buddy but when I tell the story I say "buddies" so as to somehow give the story more credibility) who own both. I like both brands, trust them both, and would purchase either with confidence depending on which company offered the product that best suited my needs.
As far as fit and finish goes, I could lay the two side by side and you couldn't tell any difference between them. Regarding reliability, my 13 year old Bushmaster finally suffered a failure to feed at the range (in my wife's hands) a few weeks ago, but I literally haven't cleaned it in well over a year, just to see how long it COULD go without any cleaning at all. (Nah, actually I'm just lazy) Broke it down, cleaned and lubed the carrier, reassembled it, and continued without further incident. My RRA has never malfunctioned, but it's only a year or two old.
One of my two buddies had failures to feed with his RRA when it was brand new, but he had just purchased it, walked out of the store, and gone to the range. Similar drill, broke it in half, removed and lubed the carrier, reassembled, never another problem.
The other buddy, with a Bushmaster, has never had any issues with his.
I think your buddy (buddies) either has issues with his ammo, or with his cleaning regimen, or maybe even his magazine. I wouldn't take his advice very seriously.