I didn't listen to them all, but I didn't find a riff that really grabbed me to actually pick up the guitar and learn it.
I love their odd time signatures. I tried to record one of their tunes but found that it was taking me longer to learn than I planned for so I shelved it.
Is that down half dropped D or something? I remember tool, but only the radio stuff.
Lots of different tunings used... Some I think went down to B