I was using a basic Bayou classic turkey fryer and couldn't stand the 1hr+ it took to get my 8Gal boil rolling. I went so far as getting some sheet metal and building a shroud to keep the heat on the pot (that helps a lot btw, took about 20 min off the boil time). That burner uses a 15PSI regulator.
I started shopping for a better burner, and looked at the KAB4, KAB6, the Dark Star from NB, and one or two from Hurricane. In the end I wound up buying the Blichmann after reading loads of reviews. One thing that I noted was the KAB4/KAB6 use a 30PSI regulator, and the Blichmann uses a 10PSI regulator. That means less fuel used, so more brew days without a trip for a fillup. Nice.
I did a boil test of plain water in my 8 gal kettle from tap temp (58°F to boil and it took ~24 min)...and I only had it at about 60% flame.
The Blichmann is:
1) quiet
2) efficient
3) Powerful!
4) has an adjustable platform for handling small to giant kettles
5) can add legs to get siphon height
6) Stainless steel for bling effect, and no rusting
The only drawback I could think of is price, but time is money...it'll pay for itself in more enjoyable brew days and less time in the garage.
So...conclusion...another +1 for Blichmann.
John