Some are good and some are bad.
There is no botting site, where every bot is brilliant. You will always find one that isn't quite perfected.
I would say they are safe though, I've never had a problem with any of them, and their customer service seems to be alright, alas a bit slow.
I must say, my favourite bot would have to be Soul Wars Pro, works like a dream (most of the time).
Hope this helps.