i like tool alot, and have for many years. thats actually one of the bands that got me out of listening to classic rock so much.. it opened my eyes to greater music..
as for A Perfect Circle, i really like a nice few of there songs.. and i think they did a amazing job with 'imagine' but there still not as great as tool. A Perfect Circle have much more of a pop sound to them, more radio friendly but there still ok.
i personally think its just time to pick which band stays and which one stops going. I would much rather Tool then A Perfect Circle... it used to be the other way around but i'm back into tool more like when they first opened my eyes.
anyways everything else has already been said.
rock on!