I would recommend trying BCH first. I did BTC for four months with a Gamma and it was about as useful as a lit up waterwheel in a fishtank. Your hashrate is literally non-existent on the BTC side of things. At least with BCH, you're still technically within the difficulty range. That said, I've been mining it for Feb so far and no grab. It's still a lottery win with a Bitaxe Gamma.