Any thoughts on the 10s vs the 8s as far as low end and volume?

I got the 802s, and I love them, but my band is giving me a bit of guff about having more stage volume :P I've got a friend who will take the 8s off my hands for the same price (he was going to order them) so I was thinking to upgrade. The 10s are almost double the weight unfortunately. I may just wait on the 12s or even get a 15 or two (anyone tried the 15")? Man, the 15 is 55 pounds though, argh...