Great write up, Boris! I too have used both Minergate and Nicehash. Nicehash is the platform I find myself using most frequently because, like you, I find it allows me to earn higher returns. The one thing I like about Nicehash is when my miners build up a modest amt of earnings, they are either sent to my wallet address that I set up on Nicehash web site, or an off site wallet if needed. This way everything mined, in my case each day, is transferred into my wallet it is converted to bitcoin, thus allowing me to avoid seeing my total earned change due to fluctuations of exchange rates. The total amount needed to be mined varies by choice of wallet, more needs to accumulate prior to being sent off-site. I have a wallet with Nicehash and let it accumulate a bit before making totally painless transfers. I think the only time you aren't paying fees to the wallet provider to move and use cryptos is when using an offline wallet and transfering p2p. Watch out for some of sites that are eager to hold your BTC as their fees can be outrageous. Check how much it will cost to withdraw or move before allowing them to hold your coins, some will kick you in the cryptocrotch trying to get your money out