@philosopherqueen,
Ah, Memphis in May. What a wonderful event. Good music, great hallucinogens.
But I have to ask, who did you see there? The line up this year was wonderful - the Roots, Doyle Bramhall, Magic Slim, Buddy Guy, Lou Reed and then some. I ask because no one I mentioned played - at least to my knowledge.
As for Tool, yeah, they have a good thing going and would probably upstage Dream Theater - no small feat. But if you want mind blowing polyrhythms, jazz is the place to go. Art Blakey practically invented polyrhythms in modern western music, and Elvin Jones takes them to another level. I'd recommend any record with Elvin, which includes a lot of great Coltrane.