They have a pretty random, but comprehensive list of rider reviews. The nice thing is you can go back over the years for a given model and see some different reviews... Now, these are all rider reviews so they are heavily waited on opinion rather than fact, but not a bad place to check.
Other than that, dunno... Hard to trust reviews. Few places do more than regurgitate factory specs and sales pitches... Futuresnowboarding.com had a good magazine review for some boards, and they seemed pretty unbiased... that's about all I got..