All products whether it be computers, software or tuners will have fanboys - but that's generally because they are happy with the product. Revo are popular for a reason. Let's not kid ourselves, they might not be saints, but over the last few years they've serviced the VAG community pretty damn well. And I dare say if Poverty hadn't been over here shouting about ARP (regardless of his reasons - not a dig btw) Revo would still be the popular choice. As Al has said, competition can only be a good thing for product development. What concerns me is if people are being persuaded to jump ship and spend money for the sake of it.
It's a shame the majority of people won't look outside Revo or APR. There are some excellent alternatives, although granted dealers aren't as widespread. GIAC and, IMO to a lesser extent, P-Torque offer excellent products. From what I am hearing Evomsit are one to keep an eye on too.
My personal choice, after chatting to various people, was GIAC and I've been very happy with my car for 4 yrs. In that time I've had a couple of misfires and that's it. No huge flat spot either. Granted, the file I have is not GIAC's most aggressive map, but its very smooth and will produce 360BHP all day long.