You can boost to about 50 as a Warlock pretty efficiently. I think it took me 2 days and a few hours to hit 50... I used my Warrior to boost to get from 45 to 60 though: It's much faster since mobs start to hit pretty hard.

WC to 15, RFK to 20, Cath to 35, ZF to 45, and then I did LBRS. You can keep doing ZF 'till 50 and it's decent. This was all with my Warlock.

Yes, it's faster in the sense that it'll be more efficient than doing it by hand BUT then you won't have a pally along with them :/