I bought one of these. It took a VERY long time to arrive, and only worked for a few weeks. I contacted them for warranty repair and they simply never responded after that. I am out around $3000.
I'm not a fool or idiot. When I ordered, the marketplace was quite simple and they were the most promising option. It was only after most of us placed our orders with BFL that the trend in the market for pre-orders (and incredibly late deliveries) began, took shape and gained meaning as a deal-breaker.
The current bad actor in this is Black Arrow - and their reseller, MinerSource. They are 9 months behind on delivering Prospero X1s, and if you call or write, they tell you, "you can cancel your order, but there are no refunds. Here's a link to our non-existant terms you agreed to, which did not exist at the time."