I levelled several teams to 60 with RAF last year purely through questing and those times to twenty seem slow to me.

I don't have figures here but on average it took me about 45 mins per level from 20-60.

The first 20 levels would be maybe 5 or 6 hours? They fly past so fast i don't remember.

I have done this quite a lot though so I'm familiar with what I have to do to level a horde character. My levelling times for alliance chars would be a lot slower.