Most of those ban reports we're people botting from 6-24 hours a day. Like the poster above me stated, 4 hours is good, maybe 6, but anything more & without interaction quite frankly you're asking for a ban.
I'll be purchasing it tomorrow & testing it out leveling my DK from 66-80, after that I'll try a rogue & report back. This will be on a 4hour basis a day experiment.