It's been a few years since I tried on a pair of Rail Riders, but I've never been sold on them. The fit, for me, was very unflattering. The combination of elastic waist + pleated front + too baggy/too long made them a no-go. Basically, they weren't something I could happily wear around town or to work, and I am loathe to buy new clothes that are not multi-use.
Also, I found the elasticized panels on the waistband combined with the belt to be somewhat redundant--why would one need both? I know the belt is removable, but still... I never wear belts and I'm always annoyed when clothing manufacturers try to sell them to you with the pants :)
I'm sure they work for some people, but not for me.