After several weeks here and a couple posts I've decided to take the advice I've been seeing all over the place and order both of these.
And because I have no patience to wait for "Free Super-Saver Shipping", they should be here this weekend. Woohoo!
I'm definitely dumping the ipod on craigslist asap, but I think I'll keep the Senn HD448s - they really are fantastic with the mids and highs.
Anyway - just wanted to share my happy news with everybody - you guys rock! Thank you for being such great enablers.