Sun Valley Local's Perspective
Hey! I grew up in Sun Valley and it is rad. In the past few years, they've dumped a lot of resources into building it up for snowboarders. Now the resort offers a pipe, rails, and some pretty big tabletops. It doesn't sound like a ton if you're used to riding the giant parks at many resorts, but we're happy with the progress and the stuff they've built is legit. Most riders keep busy flying down the super steep long runs and jibbing off cat-tracks. We get the most snow in Jan/Feb. Late season offers great student discounts and awesome spring snow, plus funky bands and drunk tourists dancing in ski boots at the bottom of the hill.
I've written a few articles on the resort for TransWorld Snowboarding Mag. Most of those serious shredders know the area by the Galena road gap that has been in numerous photos and movies. Galena Pass, just north of town, is a great place for backcountry shredding if you don't mind the hike and have some avalanche awareness.
Sun Valley is the oldest ski resort in the US and also boasts the first chairlift, so there is a ton of history if you're into the old school ski town vibe. You end up staying in and hanging out around Ketchum, the town that surrounds the main ski mountain, Baldy. Sun Valley is just the name of the resort and a small village that hosts the swanky Sun Valley lodge scene.
It is a super fun place to snowboard and I highly recommend going, though I know I'm biased because I grew up there. Hope that helps with some of your questions.