Depends on the toon. If you have loom gear or are on RAF then it really helps. Some classes level faster than others. Profiles really can be the biggest game changer. From 0-80 I can't say how long it took me becuase I only use HB to get toons to 68-70 so I can max their proffessions becuase I have GB and other 80's for that. I have heard 4 or 5 people say a pally with loom gear and no raf can do it in just under 6 days with custom profiles.....which I do not believe. I message these people and all I get is the "I made it and if I give it to you the world will end and the profile will be destroyed so I can't share it with anyone" crap. Personally I would guess 10-14 days play time with minimal effort in gearing and using the better public profiles.
My fresh Pally (no heirlooms) took about 25 days. Right now I'm botting another Pally on a different account. It's been about 17 days and she's level 76 now. Other classes will probably take longer, judging by my experience from botting them 1-20. The last 10 levels take really really long.
