Actually I am just between MSR7 and Denon AH-MM400.... hopefully I get a chance to listen to both.
Depends a bit on how your ears process the music, I have had both, and still have ATH-MSR7 while I have returned Denons after 20 days of thorough listening.
With modern, well produced recordings, or "listen again" broadcasts on the web (high quality), or any other material of the decent quality, Denon AH-MM400 had so much bass presence that it was overwhelming
to my ears. I simply couldn't live with it.
Audio Technica ATH-MSR7, on the other hand, are much more tonally balanced, again, to my ears, and fast and detailed can.
They are in no way bass-shy, so that part of the some opinions issued on ATH-MSR7 is a bit difficult for me to understand or relate to.
Mine have been acquired well burnt-in, as it seems, and I am really enjoying them... Then again, as references at home I have AKG-K701, and
Grado GS-1000 (both very picky on how and what amplifier you pair them with), so this falls well into the type of the headphone I am accustomed to, and sound signature that I prefer. Having said that, do note that neither of these two headphones for home use would work to my satisfaction, being as they are, if they were not succesfully paired with the well matching headphone amp.
The thing is, most of the today's, recently produced material is of such quality that the need for the headphone that is not overly bassy, and has fast, tight and controlled bass representation, is, in my opinion, becoming more and more evident.
My recommendation would certainly be the ATH-MSR7, based on my experience, but even the whole array of reviews that, from what I have read, favor them.