Are you suggesting those in general, or just within my price range?
I've seen the 650 for ~$450, and I figure I could stretch to that amount if needed.
How different are the DT 880's from the DT 770's?
I very much like the HD 600 & 650. Of course there is more and better competition at $400 to $500 than there was at about $300.
The audiophile oriented and open DT 880 are massively different than the closed, bass heavy and mids light DT 770. More about (best flavor of) the DT 880 here: