Pros: easy to drive, bass hits low, highs are clear, great stage for a portable.
Cons: expensive, mids slightly recessed, plastic hinges
I have tried the JBL Synchros line of s300, s500, and s700. As it turns out, the low end model sounds the best to me. These are on ear design, cups are about 3 inches wide. Headband and yokes are metal, hinges and cups are plastic. I would like metal for the hinges for durability myself.
The sound is very nice for a portable, a V shaped sound curve with bass that hits very very low. Extra wide stage for a closed portable. I prefer this over some other portables like the Vmoda M80, Philips A1 pro, Sennheiser on ear momentum, and Beyer dt1350. The only portable so far I like more is the M-audio M50. At retail price these are too much, but prices are dropping to the sub-$70 mark, at that price I can recommend these whole heartedly.