Just to add a positive data point. I used SnapTravel a while ago for a booking in Berlin. It was a busy weekend, as it was the marathon weekend, and room prices were at a premium. I'd read some scare stories, so I decided to reach out to the hotel the week before I was due to arrive, and they confirmed the booking for me. I arrived early, they gave me a check-in at 11.30am, and they gave me an accessible room as it was a bit bigger.
The only problem I had was, because the rate was prepaid with Snaptravel's credit card, I couldn't charge anything to my room, as they didn't take a swipe of mine on arrival. Still, no biggy, I had a great stay and I'd use the company again.