Out of pure curiosity, why would you want a 31-band graphic EQ? Is it just something you're used to working with? I don't mean to say there's anything wrong with using one or anything, I just never have in the studio. I'm trying to think of what I'd do with it that I couldn't do with the included parametric EQs. I guess there's more bands, even though they're fixed?
I've used them to tune a PA in a live situation, or look for feedback, but never in the studio.