I got an old Tama Superstar off eBay last year that has a 13x9 & 14x10 rack toms and 16x16 & 18x16 floor toms. I only ever use 1 rack tom and I'd never had a 14x10 before so I did a lot of experimenting with it. Long story short, after going back and forth between the two racks far too many times (usually more than once per practice!), I decided I liked the 13x9 much better. The 14 is fun and has its own charms, but it has to be cranked up pretty tight to avoid just sounding low and dead whereas the 13 can be right in its sweet spot and sound tonally full and not too high.
My other kit (thin Keller maple) has 12x8 & 13x9 rack toms (w/ 15x14 & 18x16 floors) and again, I only ever use one rack, and again, it's the 13 I prefer by a pretty wide margin (the 12 has to be tuned too low for my comfort). Chalk me up as a fan of the 13x9 since I seem to be either trying to tune a 14 high, or a 12 low to get where a 13 naturally sits.
I've heard some suggest that odd-sized drums/cymbals/whatever don't sound as good. I don't know if it's true or not so as a precaution, I do a little conversion: 13" = 0.000178294 nautical miles, which is even so ... problem solved and my drum can sound good again. (3.302 Giga-Angstroms also works)