full disclosure, i have contracts with Hashing24 / genesis and hashflare… pretty concerned ill never get my money back.
now with that, im always watching this space, here are my thoughts:
Hashing24 - they have 3 year contracts at the moment, at a ludicrous price. within the mining difficulty heading up you will almost certainly never get your money back, let alone a profit
Hashflare - now on one year contracts. this one you might get your money back on BTC mining, but as its a one year contract its touch and go. currentl difficulty its about 250 days to get your money back…
Genesis - currently ‘sold out’ of mining contracts until probably late October. they were a good price with their open ended contracts, but my best guess is now they are waiting to see if the Chinese miners will be sticking around so they can better estimate the returns on their hash power then price accordingly.
I would steer clear of all of them, and dont every by scrypt / Monero / ETH contracts. Genesis MIGHT come out with a BTC contract worth looking at, but this space is a big risk.