I have asked the same question about many of these type of videos. I'm sure they don't worry about the theory and just play what sounds good.
There's one I saw recently that tried to break down the time signatures of a Tool drum part, I'm pretty sure Danny Carey isn't sat there thinking about 4 different time signatures while he is playing! It's about feel and groove.
Edit - took this from Danny Carey's wiki entry
He has also stated that when he is playing to an odd time signature, he tries to drum to the "feel" of the song and establish general "inner pulse" for the given time signature instead of fully counting it out.
I have my number one (a Yamaha 5-string I got for a bargain price) which is genuinely the only one I need. I have a really nice jazz type thing that I use for drop-D stuff, a Harley Benton 5-string fretless and a Stagg EUB.
Everything else (about a dozen or so) are unusual or have an interesting story. They all sound quite different and it's good to have them available if I want to create a specific sound, alternatively they are just pretty things to hang on the wall and are generally not expensive. I think the most I've paid is £400.
If I was to avoid touching the buttons I still need to use the door handle next to the machine!
The one pictured is looking pretty disgusting, the drip tray and below is filthy. Ours get regular cleaning and servicing.
Agreed, so much more than an octave.
I currently use mine as a phasered fuzzy synth but with the built in fuzz turned off. Mono mode, both upper octaves up quite high and a bit of modulation, sounds amazing!