If you are going to a mage, then yes to L21. That just about lets you get to L22 as a mage.
We also get power attack and critical strike HLAs (my Kensai is currenly L20, guess what I'm doing with him next level

).
The anti-paladin/mage would also be a powerhouse - I wouldnt like to meet him on a dark night [img]smile.gif[/img]
Just remember to boot everyone from your party before you start to scribe your scrolls, and erase the spells from your spellbooks if you have duplicate scrolls. Lots of EXP [img]smile.gif[/img]