Pros Incredible sound.
Very good at canceling out noise.
Awesome range of sound.
Cons Price... but it is worth it.
Summary Well, I spent a lot of time reviewing and reading about all kinds of headphones. I looked up both in ear headphones and over the ears. I chose these because they are much more portable and do not look as odd when wearing in public. When I wear them, I can barely hear any outside noise. I have worn them next to a construction site and not heard anything.
I read many reviews where people call these "bass" shy. I disagree (this is coming from a 19 year old male with 2 12'' subs in his SUV). Maybe I just got a really good pair. If you have an equalizer on whatever you use to listen (iPods, windows media player, and iTunes all have them), then you should be able to get ample bass out of these.
You also need something that is fairly well driven to play these. They sound great on the iPod, but phenomenal when plugged into my laptop. What you use to drive these will also have an impact on the bass. I have also used these with my keyboard and they really sound wonderful with it.
I purchased these 8 months ago and I believe they sound better now then they did even at 6 months. You must give these time if you do not like them. When I first got these, I paid 200 bucks, and was very sad when I first plugged them in. They had a long way to go to meet my expectations, but I was aware of break in time for audio equipment, so I waited. I left them plugged in overnight and by morning they were much much better, but still not quite worth 200 bucks in my opinion. It probably was a month or so before they really began to fill out and produce 200-dollar-worthy sound.
Bottom line is these are simply the best thing I have heard. I have listened to Bose's Quiet Comforts (which are over the ears and often compared to the SE420 model) and they do not even compare... SE420s are far better in every aspect. Shure just knows what they are doing.
I would highly recommend these to anyone who has any interest in audio at all and does not mind spending 200 or more on a pair of headphones.
Pros Perfect sound
Cons slightly bass shy
Summary When I 1st got these, I was not impressed at all, they sounded find of rusty, with too much mid, and too little bass. They took longer than most to break in, but now that they have, they sound great. The sound is true, probably more flat than the 530's, I could use the little extra thump though. I cant picture the sound being any better on the 530's. These are great great earphones, and if U want a true audiophile experience, these might be better than the 530's. Me however, I wished I dished out the extra cash. Other than that, usual Shure indestructableness, I use with Iphone and mic adapter, with 320 bit rate music. They sound amazing, a solid buy.
Pros Exceptional clarity throughout the frequency range, stays snugly in ear during activity, excellent isolation
Cons Some might consider these bass shy, pricey but you get what you pay for
Summary I purchased these when I lost a previous pair of earphones and decided to give these Shures a try. I am used to using Sennheiser HD650s when listening at home so I am not the type of person to go cheap when it comes to portable audio. The SE420s are so resolving and detailed that they vividly exposed the sonic flaws in my 2G ipod nano. I sold the Nano and picked up a Sony Walkman NWZ-A818 and that player paired with these Shures is a match made in heaven to my ears, I couldn't be happier with my portable music setup for on the go.