I won't be going any in resto... but you do gain considerable healing strength... pushback resistance, quicker healing wave, reduced mana to heal, faster Ankh's, etc.. in addition to the 5% crit.

I don't think the 20 points is worth as much as what you can gain in Enhancement, but to each their own.

5 points in Resto (last 5) or 5 points in Enhance (6-10) are the same amount of spell crit.
Enhance gets you 10% intellect, instant ghost wolf, reduced grounding totem cooldown, reduced mana on shocks etc.
Resto gets the same crit as enhance and much stronger heals.