Even if you are taking the occasional shot, it should be at 5-10, NOT at 15-30, since 5-10 is the next logical limit up. I know the BR size rules have been debated into the ground, but I'm fairly sure that 300BB + 3 months expenses is advocated for strict professionals as well as for BRs that cannot be as easily replaced using other methods.

In terms of my advice, I say stick to 3-6 for a few thousand more hands, then shoot 5-10 a couple times and see how you like the feel.