just got a 50 from Mark at Everlast. If I was a pro, I would probably get something from the majors, not so much that they are better, just that they are expected in a pro setup and part of the standard communication.
So far, and it hasn't been a long time, the 50 has been fantastic and the price fit my wallet very very well. Mark has responded quickly to my needs and concerns so a plus for customer support so far. My neighbor, who is a pro, came by and took a look at the setup and was very impressed.
I run on a 35 gallon craftsmen which is about the least I think you want.