You have to think about the demographics of different cities, too. I used to live in Denver (1990 to 1995), a very bicycle-friendly city with an amazing web of usable bike paths and great streets and a monster bike culture. I commuted on a Trek 520 touring bike, drop bars, skinny high pressure tires, Reynolds steel frame, smooth, strong, quiet and fast. But now I live in El Paso, Texas, no bike culture, no bike paths, ill-kept streets, when a bicyclist is out there it is many times a battle. Sometimes the best and shortest routes are these insane rock-strewn dirt streets, parking lots and sidewalks, and even the good streets are in need of repair. When we first came here I started commuting on the 520 - no dice. I got a Trek 4300, a relatively low-end hardtail, dressed it up and <<bingo>>. So, my 520? Denver OK; El Paso, not OK. My mountain bike? OK in both cities, but not quite as fast in Denver. The OP is correct.