I have to admit that most of the comments along the lines of "band (fill in the blank) should be on the list" are unsupportable in my opinion, but that is just my opinion. BUT, more importantly, again: I stated the biggest value of this list is in identifying bands you've never heard of to check out. Trust me on this, you will find some incredibly good music if you explore this list.
Finally, who is Greg? It's already been answered re: Synphonic, but I will add this. I hope by now you know that I know a LOT about prog. Greg is one of the few people on the planet who knows WAY more about prog than I do. Doesn't mean you have to agree with him re: Crimson or Floyd, but at danger of being repetitious, trust me, check out the bands you haven't heard. You'll be glad you did, as will I, as that is the main reason I posted it
check out the bands you haven't heard
check out the bands you haven't heard
check out the bands you haven't heard
check out the bands you haven't heard