Tim Alexander (Primus) uses a 20 on the LEFT and an 18 on the right. Bang-a-rang. I've used both these sizes and it's pretty sweet. I have a 22x18 Yamaha Maple absolute, a 20x14 no name maple drum from the 70's, and an 18x16 Yamaha RC floor tom that I turned into a bass drum, none of which have "jazz" tunings. It's always fun to decide which one to bring out, they all offer something, but lately the 20 has been leading the pack. And since it's a p.o.s. at it's core it has some sorta crazy soul behind it, and I don't have to treat it as gingerly. The 22 is just a bitch to bring out(but it sounds great), although I do lug it anytime I play a bigger venue. My next kit will have a 20x18(amongst some other cool sizes), or maybe even a 20x20. I am just loving the feel of a 20. I theorize it's cause the kit I cut my teeth on for the first 5 years had a 20...
Also, Danny Carey of Tool uses a 20 and a 22, but I think for him the bigger drum is on the right. I could be wrong.