I saw the 2010 Patriot Center show with Jay and I felt he was somewhat marginalized because of his new role as Percussionist compared to Ratdog Jay, but he really wanted to do Primus so he is and Phil's comments support this interpretation. imo

Did you see that guy hopping around back there? He sure seemed like he was having a good time to me...

Also, regarding the decision to go with a percussion rig as opposed to a traditional kit, I seem to recall an interview with Jay where he stated it was his call as to what to play? My mind could be playing tricks on me, though, with regards to that...

No doubt they didn't know how to play with each other, wasn't it Russo in the dead.net interview (a great read, btw) who stated that playing with Jay was the first time ever played with another drummer?

None of this is to say that Joe isn't thriving on his own, of course. He's doing a tremendous job back there and I'm glad to see it.

Joe also said that Jay was great help to him when he was is the "cheat sheet taped to his rig"phase with the band.

More I think about it, my best guess is Jay was thinking that Joe was ready to do it on his own, and when the Primus offer came up, it was too good to turn down.

My guess is JK had the same type of feelings when Phil and Bobby called. He loved DSO, but when an offers to good to turn down, changes are made!