Finally happy with latest 17.10.3 drivers (rigs are quite stable) with one exception - I use Claymore's settings for voltages and frequencies (not AfterBurner or something similar) and have to run it twice. This is because of low hashrate after first start for some cards - cards start with 23-25MH, but after stopping the miner and running it again they sdstart at normal rate. It is a clue for me.