thanks for the input, I think I'd give it a try....

For the bad points:
1. They're looking for same gear. Since I'm dual-boxing, I'm not really doing instances, so I rely mostly on quest rewards, which both toons get anyway.
2. Can't heal the main when on moonkin form. Well, I play on alliance, so when things get REALLY rough (even after trees + ele go out), I can shadowmeld, let mage die, and then rez LOL
3. Ability to use mage's full potential -> this is very true. But I find that mage goes OOM really fast, so maybe it's good to conserve its mana a little bit.

I plan to spec druid resto when it hits 80, and this will be my first attempt at serious healing. Seriously, who doesn't LF healer these days :P