MY biggest concern aside of not getting the miner at all, is to get something not as advertised and then how to prove it.
This is my concern as well.
What happens for example if I order a KNC Jupiter and find that it is only hashing at 235 ghash or something like many on the KNC forums are reporting.
How would I prove that this is the case and how would you handle it?
What if something is damaged during shipping?