I agree with Maxvla. I thoroughly respect the 598 for what they are even though I have some high end gear. They are not dull but rather do a good job at exposing poor files and recordings unlike the CAL! you mention which will mask these things. 

Yeah I think the user here is just used to BOOM BOOM BASS

These cans soundstage like crazy, if you feed them with proper stuff. They kept surprising me when I turned my head because I was sure I heard something from behind me. What were you feeding these with? On low quality source/amplification, they sound somewhat dull indeed though and way too mellow. 

As somebody who owns and enjoys both the CAL! and HD598, I really don't agree with your review. I'm thinking you prefer a less laid-back presentation and smaller soundstage, and perhaps more bass.

Xinze: The CAL! isn't really a boomy headphone though (unless under-driven). I do think you're on to something though. dz1k needs to track down some Foster-era Denons.

Rem0o: Agreed on the source. Also dz1k, what type of music do you listen to?

I think I do not like HD598 for most of my genres anymore but still use it for daily work such as video clips, movies, games, etc... for serious music I think the review is right, ones should look for other cans. The sound is really annoying me now, little bright, vocals some times are recessed, bass is there and tight but can not go deep, treble is roll off. The positive things which are very comfortable, light weight, fancy look, fairly transparent and suit for movies and games because of wonderful sound-stage of theirs. I think it is the time for me to move to higher headphone.