I remember it vividly, and was there in the flesh to witness it!
It's a bit difficult to prove the point when there's such a clear disagreement, and I can only recommend digging up threads from on here at the time, or catching a few games from the 08/09 season or from the first half of the 09/10 season. Still, you have your own opinion, and I can't force you to change it.
He wasn't Roy Keane, but he was putting in some fantastic performances consistently. Chelsea, Arsenal, Liverpool, in Europe...you name it. I've said it before, but I vividly remember walking out of Old Trafford pretty much after every game during that 08/09 season thinking, "feck me...Fletcher for man of the match today - that was a bit ridiculous actually...". It was quite a unanimous thing amongst fans that he was brilliant at that time, and it was made all the sweeter given the stick he received earlier in his career.
His rise to form started in 06/07 though, actually. He had a cracking game against Liverpool and, though he couldn't cement a place in the starting line up ahead of Carrick and Scholes, he had some other really good performances that year. Same goes for 07/08, though they were few and far between from what I remember (injuries). He's basically been very unfortunate. He never had the ability of Scholes, but when he came into his own, he was no doubt good enough to start for us.
As you say, Brown was absolutely fantastic in 07/08 and, when fit, Fletcher was at that level. Absolutely fantastic is good enough for me.