Risk Vs Reward....

Set and forget = Nicehash

Nicehash is going to be always to lowest paid service, because they are reselling all the HASH you are giving them.

But is it worth 5-10% to use a different miner software and pool?

check out awesome miner free version, set to 24 hr actual profit and put ahashpool and niceminer as the mining pools.

Then you can see how much money you could be loosing using nicehash, currently my rig is showing in the last 24 hours

$11.80 per card on ahashpool
$ 8.88 per card on nicehash