Pros: Smooth...I guess?
Cons: Muddy sloppy woolly bass, no seal, microphonics, tips fall off easy
Really a horrible set of headphones for the money.
I got these way back as an upgrade from stock ipod headphones and was blown away by the bass. At the time all I wanted was bass and boy did they deliver. At the time I loved them but as my music interests grew and expanded so did my realization that I had horrible headphones.
Last year I picked up a set of AWEI ES-Q3 off of Dealextreme for like $5 and those were considerably ahead of these Bose in terms of balance.
The tips are held on with a small groove which means they will fall off if you put them into a backpack or they fall out of your ear due to their lack of sealing. I can't even remember how many times I had to frantically look for the tip that fell out while trying to store these in the little carrying case it comes with.
The carrying case is another awful addition. It encourages you to tightly wind the cord around a square and squish the earphones into the small notches to keep them in place.