This is pretty accurate. BJJ'ers are in general (usual caveats of some judoka being world class on the ground, some BJJ'ers being world class in throwing/takedowns :icon_chee) much more sophisticated and smoother on the ground, but less explosive. The judo top game is actually pretty good, but the bottom game is (usually :icon_chee) much, much weaker than that of BJJ.
And judo clubs drill breaking turtles - its arguably the only thing they're as methodical about on the ground as BJJ'ers are. Any competition judoka (as opposed to recreational judoka) will learn three or four turtle break downs (that can be done in 5-10 seconds tops) and drill them as a series of discrete sets until they're as automatic as a throw. The reason for this is of course how common the turtle is in judo, and the very limited time (rarely get more than ten seconds, often only five :icon_sadyou have to break it down.
Its the one aspect of judo groundwork which is more advanced than BJJ groundwork - the BJJ instructor I trade instruction with says he learned all his turtle breakdowns from judo. There never was the same need for them in BJJ, as you have almost unlimited time to break the turtle, so you don't need the same algorithmic approach.
