JP does contribute alot, he even produces the albums along with potnoy... i wasnt trying to bag JP... the thing is most people who replied here are to caught up in sweep picking and tapping, and fast and etc etc...
they are both technically amazing, and both have lines that the other doesnt seem to play much... BUT
about romeo, he appears to arrange and orchestrate alot better than JP IMO, he is a total musician, ad people here are missing that point because of sweep arps and tapped licks, those are great... but, Romeo is way more than licks, the music really is MJR, again IMO...
you can replace anyone in the band, and it WOULD chance, but take romeo out and the band is over...