Exactly, mixing sites is the best.
I have decided to play in GGPoker most of them, I usually have better results than in other sites.
I play them in
partypoker too, becouse a special situation here- There are daily scheduled satellites to all tourneys, directly, or in steps, very cheap, and the most important, they generally have an overlay of around 50%!, sometimes even more, and other times just almost no overlay, but is what i do, play satellites with big overlay, use tickets to MTT, and sometimes directly play deepstacks MTT, with any overlay, your money worth more just for simply pay the buyin.
iPoker is soft too, but, i use iPoker for 3x1eur satellites, then use that 1 eur ticket in twister poker, is very soft, and its super common to get 8x prizes!