Phronesis
Headphoneus Supremus
I too have the 99 classics and the clear. The only thing I find with the classics is sometimes the bass can sound sloppy or bleed into the midrange a little. The clears only gave out the exact bass that was from the recording.
My impression of those two headphones is similar. The Clear is quite neutral and clear, with an energetic but not boomy or bloated bass. To complement the Clear, you need something which deviates significantly from neutrality, and need to be careful to choose a deviation which isn't unpleasant.