D3 and K5 are not comparable, with D3 you had 100+ coins/chances to mine and hoping that one of them could gain price and make roi (luckilly my case)
K5 is only for CKB, but that could change, maybe more coins will occur on nervos algo
What coin did you mine, that gained price, that allowed you to breakeven or even better on your antminer d3?
Dash was the ONLY coin worth mining on X11, then,now, ever whatever, imo
Speaking of the Bitmain Antminer K5, my miner mined 2600 CKB coins in 24 hours if anyone wants to read about it / hashrate logs etc -
https://voskcointalk.com/t/analyzing-mining-profitability-of-our-bitmain-antminer-k5-nervos-ckb-asic-miner/210