Why? Do you seriously think they'll ever ROI?
who knows.. I've had 2 jupiters for 20 days and mined 37.5 BTC,
if I held all the coins until today I would have 50% ROI as cash now but I was selling into the rally so more like 36% ROI as cash so far
had some downtimes and one miner running about 80% until today's FW brought it up to par
YMMV - food for thought - FYI, etc
I think you're calculating that incorrectly. If you bought two Jupiters for 58 BTC each, or 116 BTC, and you've mined 37.5 BTC, then your ROI so far is -67%.
I do think KnCs stand a chance of having a USD ROI. At least I hope so since I have one (and paid USD for it, USD I wasn't planning on buying BTC with). Will they ROI in BTC? I'm not sure.
Both KnC and Hashfast units might ROI over the long, long term. But KnCs will have a huge head start, hopefully covering most of their initial cost before HF even ships.