Well manually questing is always faster than manual grinding provided you know which quests lead onto good chains and which ones are just not worth it. The same goes for HB. However I have noticed on certain classes in certain areas, that the bot will attempt very ambitious quests for your level/gear/class and will almost certainly die every attempt. So far I have gotten to level 24 ish while questing without 1 death on my mage (leveling gear, greens etc). I do not know what it is like up to 60. 60 - 70 is very fast if you get the right profiles. There is a 67 - 70 profile that got me from 67 - 69 via questing, and for the last couple bars of 69 it just grinded till it hit 70. 70 - 80 can be a little tricky. 70 - 75 is completely AFK-able via questing, however 75 - 80 is probably best via grinding.
I have done it this way on 2 of my chars (rogue, druid)
Pins.