And yeah if I was 16 I guess this kind of thing would have been extra cool to me. But I was already into a bunch of other crazy stuff at the time to fill the teenage music-nerd need to consume weird conceptual shit. I got into Zappa and The Residents and classic era prog bands.
Plus I obsessively went down rabbit-holes of semi-obscure bands that really clicked with me specifically (Jellyfish was a big one) to find every last b-side and side-project I could.
My music-nerd phase had very little time for metal though. Dream Theater was about the extent of it.
based on these initial listens, Tool reminded me a lot of The Mars Volta. Similar metal-prog thing going on with crazy concepts and nutty experimental song structures. I've only heard a couple TMV albums but I definitely like them more than Tool.