Still own two pairs of these! Still one of my all time favorites.
I actually find the Tony Bennett version to sound a little better (can't really confirm it) and that's the one I use.
I probably haven't used them without the M50 pads in years.
The biggest negative of these is that I MYSELF could never use them without an amp.
Even my HD-650 does better without an amp somehow.
The bass on the DJ100 is very underrated. I think it's nearly flat down to 10hz and you can actually hear/feel the low bass.
The KRK KNS-8400 also has impressive low bass and that's considered bass light to some.
There is bass on the DJ100 that's basically missing on the Q701, HD650 and the DT-880. HD-650 actually has pretty good low bass for an open headphone.
My most used headphone though in the last 2 years has been the HD-650 (I'm mostly retired from headphones sort of).
Someday I want to try the new Koss Pro4S but it's too expensive for me right now.
I asked Koss for a review unit loaner, but no reply. I guess they don't trust me
I'm their #1 DJ100 fanboy too...boo
BTW I can hear differences between all my gear changes with this headphone just like on the DT-880!
I can hear them a little on the HD-650, but not as easily.
I wish Koss could somehow figure out how to make a portable open headphone using this driver.
With this driver they could easily make a better sounding headphone than even the HD-598 (which I really like, but ruined with mods).
This driver is held back by the enclosure I think, but still manages to sound pretty amazing.