No.
My Cakewalk UA-25 EX (by Roland) does a great job recording and powering low-impedance headphones – I love it, but with my new Sennheiser HD 650 it doesn't work great, unfortunately. Better than with iPod or direct connection though;)
Output sound lacks mid-range and most of high frequencies, snare drums sound muffled and don't give a proper groove. I hear a lot of bass (I think Beats Audio should sound like that). Volume level is enough from 2/3 to full throttle on most recordings. On quiet recordings it's not enough. No complains – all instruments sound distinct, but the overall feeling is that something is wrong here.
Tried Creative E-MU 0404 USB today, it gives more mid-range and high response but doesn't drive them too. It has an external power adapter while UA-25 EX is powered by USB only.
I consider purchasing ESI Prime or Dr.Dac by Audiotrack. It's what people suggest.
Hope it was helpful.