Summary: play music professionally.
these sound great.
been through 3 of them in 90 days.
buy the insurance from guitar center - if you're on tour with these and the left side goes out (it will) you'll be screwed for a week.
seriously - buy these - but DO NOT hit the road with out replacement cables.
and don't use them for anything other than rehearsals or shows - if they crap out on you mid-set, that's on them... if you lose a side to WTF you're gonna be even more pissed.
Pros: great solid flat sound, comfortable, isolating
Summary: I got my pairs (plural) because my last pair of tried and trusty EC-4s bit the dust.. losing the left channel as they tend to do over 3 or 4 years. In the past, I'd send $100 dollars and the EC-4s to Shure, who'd fix them and send them back. Good to go.
Unfortunately, Shure has end-of-lifed the EC-4s. Boo! So rather than fixing them, they replaced them with two brand new pairs of SE425's-- right off the store shelves.
Pros: Great sound, Great brand and customer service