Pros: Excellent sound quality, fit, and soundstage
Cons: None, from my perspective
I'm not as experienced as other members here in headfi, but I can assure you that you won't be disappointed a single bit if you are coming from sub 200 dollars price range. I've been using earphones all the way from Apple's stock earphones, Audiotechnica sub 100 dollars, to Sennheiser sub 150. This SE425 just rocks. Of course, I got a deal for used pair for 152 USD, but that doesn't mean the sound quality degraded (actually, the previous owner burned-in, so it was a good sounding IEM from the beginning for me.)
One thing that I like about this design is that you can sleep while wearing these without a problem. It doesnt protrude from your ear, so no worries about them breaking.
Have a great listening experience! :D