Considering the K16 design has NOT been finalized by Bkkcoins, I think Terrahash accepting pre-orders is premature at best.
I'm not asking anybody for pre-orders, and I have more posts than Terrahash and joined the forum slightly before they did ( I think).
Post count isn't everything. Heck, I have more posts than you, and I'm an idiot sometimes. TerraHash has few posts, but that's cuz they're all on topic concerning his thread, or the Klondike project.
For the longest time, they did not accept pre-orders or any money of any kind. The only reason they recently starting taking pre-orders was because people were practically begging him to take their money to ensure 1st batch slots. My understanding was that those pre-order money would go towards purchasing a 2nd batch of Avalon chips, so they could shorten the down period
if when they sell out of the 1st batch of orders.
You cant be too cautions, but not too many people who have looked into them seriously think they are a scam.