https://www.youtube.com/watch?v=nHemRGEXwIk
This guy also echo's my sentiments. The BTC network is getting pretty tough on mining. BCH / UNIT / LCC may work out better and arguably at some point if there's another rush on Bitcoin and the miners on ebay soar there's potential there too....However at the current price I'll not be buying, definitely not for the end of March!
You'd probably do better to by some BTC / BCH and hodl and go for whatever comes next....
Though that may be a while, as whilst I think Bitmain probably has a better miner, they've little in the way of competition atm, so why break something that's still profitable for them!