The ban-rate is higher than Runescape's I believe. Blizzard has a really good detection system called Warden. Their staff are also usually more dedicated. I am not sure if you would get perm. banned your first offense though.
Blizzard is pretty flexible with user offences, since by banning botters willy-nilly they'd be losing $15/month for each person. I think they give you 1 chance, then it's a ban on the second offence.
The best is easily honorbuddy, I managed to run quite a successful botfarm (mini) of around 20 bots successfully farming. I made quite alot of profit I must say