Tax form 8880?

I was trying to file our taxes and it says I can't complete it til the 23rd when this form 8880 becomes available. That's cool.
It pertains to money that you have put into a retirement plan.
My question is, if you filed last year, with this form, for the "Saver's Credit", how much of a difference did it make in the amount of refund you got back?
I'm liking the number it's telling us now, so I can't imagine getting more, lol.