I think the Antminer V9 is an underrated and under appreciated machine. It has comparable performance to the S7, and is much cheaper. The price of an S7 today is $899-$1200 dollars vs the V9 at about 500. It is an affordable upgrade for hobby miners that want to take their mining experience to the next level. You aren't going to have to rewire the house to be able to run one or two of these. For someone with cheap electricity it might even be nice to have a few of them vs an S9. Sure the initial costs for all the power supply units would be a lot, but if there is some sort of machine failure, you still can run at 80% while fixing it. Also, having a few V9s would allow you to mine on multiple pools at a single time vs a single S9. Have one on Bitcoin, one on BCH, Digibyte, and so on. Plus, a V9 is much more profitable than an S3.