Thanks for your help / advice guys... always better to hear other peoples views.

I am hopefully planning add 2 x AMD rigs to compliment our existing 580 rig...

and then start adding Nvidia rigs aswell to make a mini farm.

I have not looked into the 1660ti so I will do some research into these... but its looking likely I will have 1070 and 1660ti rigs going forward.

Do you guys mine to coinbase wallets and extract onto a Ledger Nano or sell/trade weekly/monthly?

Thanks