I've been thinking about expanding my mini farm to include some P102-100 cards. They seem to be one of the fastest cards on the market right now (aside from modded 1080Ti).50MH/s mining ETH
at around 180-200W is solid performance. My only concern is that the card uses 2 x 8-pin ATX connector, which would place additional requirement on my PSU set-up.
A preview of P102-100 card: https://www.bitnand.com/nvidia-p102-100-gpu-mining-preview