ROI will considerably change over time. It maybe awesome (extreme high) at the moment, but might be terrible some days in the future (due to unbelievable high number of masternodes and low price of Protoncoin).
all things end eventually... even Gobyte, that was a good investment but guys are evil to put 850 MNs

I still get me 4.275 coins a week for the last two months from my 10% share. I imagine those whales are rich now