I've happily used it a few times this year - I almost always check their prices against bigger sites like hotels.com and they can usually provide a lower price if I'm booking after 6PM (before then and it's often the same price you can find directly from the hotel). More importantly, I very much value their curated set of "advice" about the hotel, and find it significantly easier to filter than sites like booking.com or otherwise.

Their mobile app is nice, and the flow is extremely smooth. I did once have to wait 45 minutes at a Best Western for their customer support to fax something across before I was able to get my room.