I haven't tried either yet, as I just got my wii. However, I have ssx coming in the mail and I plan on getting Shaun White when it comes out. I'll post back in a few days, after I've played ssx a bit.
Better late than never? Well, I wanted to get familiar with ssx before reviewing it. It's definately a lot of fun. The only semi-issue I see is it's probably too easy to recover/land jumps.
I'm gettin shaun white's snowboarding just because it will be relatively fun, not because of the name. I personally can't stand mainstream pros, hopefully it doesn't turn out to be like Tony hawk with like 324324 versions of the same thing. :P