Those considering buying: VirtualMining is ActiveMining is Ken Slaughter.
To spare yourself some grief, please read this CoinDesk article:
http://www.coindesk.com/mining-hardware-companies-miners-roundup/ TL;DR after CoinDesk guy asked for a refund:
The cheque was sent back with an accompanying letter clearly stating the correct spelling of the recipient’s name, just to be sure.
However, mid-March a new cheque arrived containing the same misspelling and, this time, it wasn’t signed either. At this point I started to wonder whether these errors were being done on purpose to delay the refund.
Declining my request to have the funds wired to my bank account instead, VMC will now be sending a third cheque (after receiving the unsigned one back from me).
So, maybe with some luck, some four to five months after applying for a refund, I will actually get my money back.
Further lulz could be had in multiple ActiveMining threads in the Securities section.
Enjoy.