I don't disagree vehemently - don't like the "c-" word, but still - but the last part isn't really apples to apples. He's one of the three, the trinity, that has been there from day one and persevered, at least up to a point. Kevin would be in that group, too, but he bailed early. There's no "pre-JR" and "post-JR" because he's not the first. Hell, he's not even the SECOND. And CONCENSUS, there's a JR record and a non-JR record in the discussion for "best DT record". There's no MM record in that pantheon, at least not across the entire fanbase. We did that list here not that long ago.
Yes, I agree that it is an important point.
But if, when we want to discuss DT's sound, the band's paths, choices etc. You can't ignore JR's impact on Dream Theater.
I believe that if it is possible to establish a trio of classic albums that many fans would not object to, that trio would be I&W, Awake and SFAM (although I myself am not that fond of Awake, but that's okay). I find it quite symptomatic that two of these albums are with KM and the other is the FIRST album with JR.
I'm not trying to say that JR ruined DT, that's not the way of reasoning.
But it is undeniable that after him the band changed. And although he's been on some great albums, none of them are a huge consensus, except the first one.
I have rarely seen a discussion like this. On the other hand, how many times have I seen the following theoretical path "Dream Theater was a badass band, MP left the band and they became shit. The end"? At least hundreds of times? There is an absurd discrepancy in my opinion. That's what I'm referring to.
Edit: The idea of the trinity is interesting, but let's be honest. It is not really a trinity, not in the sense that the three entities occupy equal roles. If JM says "guys, I'm tired.... carry on without me" there won't be a JM era and post-JM era.