I've had one for about five years. I have ran about 3k rounds thru it with no real problems, it is an Ohio Rapid Fire. ORF is considered middle of the road in terms of quality and workmanship. Mine is an early gun from the first batch made, it was cheap at the time. It looks like a 3rd grader riveted and stamped it but the park job and parts were all fine. The nicest ones I have ever seen are Ohio Ordnance and Black Bear and they are expensive. I do not think Ohio Ord is making an guns for the civilian market at this time, they have contracts from the DoD that are keeping them busy.
Todd Grove(the owner of ORF) has fell out of favor with the 1919a4 crowd, he was a mainstay on the board a couple of years ago. As he got bigger and expanded his product line, quality may have slipped a bit. His desire to involve himself in internet/board drama is gone.
What you get in terms of workmanship and quality depends on what you want to spend, the low end is about 1k for a gun the high end if around 2.5k for a gun with accessories. There are at least six good builders out there at the moment. Stay away from anything built by Hesse/Vulcan.
You will need some form of mount to enjoy it properly, 1919A4.com will fill in the details for anything and everything and it is a pretty active board. Prices for guns have dropped a bit in the last year or two, but prices for anything related or an original mount have at least doubled in the last five years.