[WhiskeyJacks]

I have to say I am using the T70p with the ALO PanAm and it sounds fantastic, for a closed headphone, I usually prefer open phones, and usually that is what I use. I am going to say I really like the HD600 for laid back all purposes, and they do everything pretty well for the most part. But the T70p are some of the most open sounding closed headphones I have had  a chance to hear. With a very neutral presentation but still very enjoyable, great detail and resolution. The Bass is said to be on lighter side and it is lighter, but also very extends very deep and is very tight, the clamping force is very comfortable along with the weight of the headphone. The Mids are more natural and definitely have a nicer timber and accuracy then  the DT series, and the treble is brighter but not harsh it is very well extended and detailed, I would say the Treble is some of the best I have heard on a headphone but I actually like teh mids alot with this phone it is the best midrange i have heard from a beyer so far, but I have yet to hear the T1 and the higher end beyers. I do suggest this fort a great overall comfort and sound quality out of the headphones I have listened to...both open and closed. The modded T50RP the ZMF X Vibro though is less portable because of bulk is also a very enjoyable, smooth, detailed headphone with some great bass impact and midrange, really love the mids of this headphone, and of course the overall aesthetics.
 
EDIT: The T70RP can be driven from my Ipod easily, and sounds very good, but it does scale with better gear very well for a lower impedance headphone. I use it with the JDS Labs C5/ and Meier 2Move shortly with a rockbox Ipod as my source playing all higher quality tracks and I have to say it sounds beautiful.