While I haven't tried the Denons (2000, 5000, or 7000), I have lots of experience with the 2005 DT990 250ohms. There have been many reviews about how the 990s are overly bassy and have a problem with sibilance, which I find to be true with some amps, but not all. The 990 can be very sibilant with some solid state amps like the Corda Headfive, but this is not at all a problem with the Compass. With the Compass I find the 990s to still have a strong bass presence, although not overwhelming to my ears. The problem with sibilance is almost nonexistent in my setup.
I listen to many different types of music, although primarily rock, blues, funk, jazz, and the like. I find that the Compass and 990 pair well with this music to give it a very fun sound, although not in any way neutral.
In short, I really like the combo, but if you want more info, I reviewed the Compass and its HDAMs with the 990s in much greater depth in the Compass thread. You can find that review
here.
I'm sure you'll enjoy the Compass no matter which headphones you choose!