I don't think pre-TUF fight records are that big a deal, its mostly minor-leagues A lot of guys like Jorge and Pete Sell had fights and records, and lost big time on the show and have done nothing since.
Amir had "no pro record", but his fighting was well established, otherwise he never would have made it to the show.
On paper, Amir may be the "most impressive contestant, ever", but doesn't really mean a lot unless he keeps winning. Which I hope he does.
I think you are a bit confused. I didn't say that Amir was the best contestant ever on TUF as clearly there are a lot of fighters that are better than him that came off the show. I'm just saying that his run on the show is more impressive than anyone elses.
Also, Pete Sell and Jorge Rivera were on the comeback season. Both guys had a couple previous UFC fights and were fighting against other UFC veterans, so it's a little different.
I think pre TUF records actually do matter. Just look at the guys who have won the seasons. Forrest Griffen had wins over Jeff Monson and Chael Sonnen pre TUF and a fight with Jeremy Horn. Diego Sanchez was 11 - 0. Mac Danzig had over 20 fights. Michael Bispbing was 10 - 0. Joe Stevenson had about 30 fights before the show. So experience is definatley an advantage.
Also, Amir wasn't well know before the show.
"I does work" - Brett Rogers
“I don’t know what kind of technique was used there, but there was a lot of kicking and punching.” – Jim Brown