Several years ago I was shopping for a hardtail mountain bike, and it came down to a Gary Fisher Hoo Koo e Koo or TREK 6700WSD. The geometries felt about the same to me, and they had similar components and prices. I bought the TREK simply because I'd enjoyed my first TREK mountain bike, and because I wanted to buy it at the LBS two miles from my house, which has provided me great service. Some friends have the HOO KOO's and they have had good luck with them. Can't address the other models. Have fun shopping!