Thank you for the detailed review :) i mine just like you wih gpus and genesis too it the best strategy i think :)long run there is no other investment i think in the whole universe now wich generate a 100% return easily over year this is insane :D it dont make sense to invest anywhere else then mining contracts or gpu mining rigs , i think everyone who is not doing this is losing big opportunities , maybe contracts will be sold out just like gpus nowadays. How often do you upgrade your contracts ? is it random or do you have some system like % of mined coins you reinvest to keep the difficulty irrelevant ?