Ohio Rapid Fire aren’t the highest quality. Mine leaks rust and is too tight on the back plate. Plus they followed old rules and welded the plates. That said, it was ORF that brought us common folk the first affordable semi 1919.
One popular builder, and I won’t name names, has done some pretty sloppy work. Most of it is cosmetic.
As already noted, KMP sells parts, so a KMP labeled home build may run the gamut in quality.
Ravenna builds a nice gun and is the leader in value. If you’re working and value free time, it’s more cost effective to send a kit to them and get a working gun back. Truly a case where throwing money at a situation makes a ton of sense.
There are a few small scale, highest quality builders, like Lucky13, but they are low volume because none but the most fanatic will pay double the average price for an example that far exceeds factory quality.