Originally Posted by ShneekeyTheLost
It's rather important to the class, because it demonstrates a graduating mastery of the abilities. Not only do you gain more uses per day per devotional, but it also becomes easier to use.
I am afraid I stated my opinion rather confusingly. I was just saying that you didn't need to link the progression of being better able to use magic (Spell-SLA-Su) to how often they could use that spell or create that effect.
As for the devotionals chosen, just be careful about which spells you choose to replicate, although I do think you will be.