I've done it in Hualian a bunch of times and Wulai once. I thought Wulai was much more harcore=higher flow, steeper, rougher terrain, they just toss us down rapids like floating log, and it is much closer to Taipei. But if you are also looking to do a Hualian trip that might be more convenient. In Wulai you have a pretty nice hike back to town at the end. If you are into river tracing as a sport, then I think Wulai is more challenging. SOrry I can't comment on the services, I always have someone else book in Chinese.