Presto and Test for Echo are both somewhat weak overall, although both have a couple of standout songs. Plus, neither sounds that great - Presto is too thin and bottomless from a low end standpoint, and Test for Echo sounds too cluttery and jumbled, as opposed to the terrific sound of CP.
Roll the Bones has a few weaker songs ("Face Up" and "You Bet Your Life") but the five songs they have played from it live are all at least very good, and "Heresy" is a nice and widely overlooked good songs, and I like "The Big Wheel" quite a bit, as well. "Neurotica" needed a much stronger chorus, but I like the vibe going on in the verses. From start to finish, RtB is a very nice listen.
But, yeah, CP is the obvious standpoint of that four-album stretch.