Genesis Mining just like a couple other are still working but can barely give you a chance to ROI so I guess I must say, Stay away.
I would say it this way
* X11 / Ethereum contracts are working very well at the moment
* Current sha contracts are too expensive, but I heard from support that price will change in the next few days
My experience so far is positive if you buy contracts early (within 2 weeks after new prices are out). My old sha contract is ok, and X11 / Ether contracts are going very strong, too. Being late in the game will let you lose money.