Another thing to note, is the warranty period. I believe every mining device should be under warranty for the whole period until the device's break even. If an FPGA board dies well before break even, it's a lose-lose-lose-lose situation. In this field, FPGAs ar far behind IMO compared to GPUs
Last but not least, the reselling price should be taken under consideration. An FPGA board, is specific to Bitcoin mining. If anything happens in that field (e.g. new and better board comes out, bitcoin fails, etc), no one would want to buy it. On the contrary, GPUs can be sold quite easily and are independent on bitcoin.
We would like to let all our clients know that, in case of Bitcoin failure, we will make all our units OpenSource,
and thus making it possible for the clients to sell their units to various industries at almost certainly higher price
than they purchased it in the first place.
Regards,
BF Labs Inc.