Folks overuse this word a lot. Cointerra is not a scam, the product will ship. On time? Who knows, but it will.

To the OP, if you can find a first or second gen KNC unit for less than original cost, it'll do you well. I'm on the fence about Feb/March 2TH mining myself. If the value of BTC stabilizes at $500, it seems to be a good idea to get a miner.

Holding BTC is always a win in the long term.

Keep in mind, you can re-sell your mining equipment and more than likely break even or make profit. $5k KNC units are going on ebay for $10k right now. The same will occur in Feb/Mar, ESPECIALLY if BTC rises.

At worse you will find a way to break even.