Finally getting around to posting a review of these beauties, so here goes.

I've been using these as my JOAT cans for work, music, and on the go listening. Their tank like build quality and price really makes me not even think twice about throwing them about or mistreating them. So far no notable wear or scratches, and no loose parts. Only issues I've had so far is the earpads can be a bit stiff on first wear, and it feels as if the foam takes a few minutes to adjust to my head. They aren't perfect with glasses to be honest, but I'd say a decent bit better than the Ultrasone HFI-580s. Happily they offer some isolation from ambient noises, though the overly long cable can make it awkward when on the go.

Sound wise they are quite on par for ~70 dollar headphones. Overall I haven't found a genre that sounds horrid on these, and sound decent out of various devices I have tried, so I have qualm with taking these on the go. I'd describe the sound as bass heavy, mids sound just fine to me, but the highs can get a bit harsh depending on the music, so your mileage may vary. I wouldn't call em laid back by an stretch of imagination. I find myself taking them off after a few hours of use thanks to the combination of harsh-esque highs, stiff earpads, and some clamping force.

Overall I consider these fairly great headphones for the price, and wouldn't dissuade anyone from buying them.

A great set of portable closed cans for the go.  With a lower impedance than their predecessors these headphones can be run of nearly any source.  Although the sound stage is limited the overall sound quality is quite pleasing.  
 
For full review:
http://www.head-fi.org/t/617578/sennheiser-amperior-review#post_8516525

I was a bit surprised when I discovered that a 3rd generation Kindle could in fact play mp3's.  In the spirit of head-fi I decided to review this rather nifty addition to the kindle.  Keep in mind that I'm only review the audio portion of this device and not the device itself.  To start out the music player feature on the kindle is "experimental" meaning that it is a feature that might be fully implemented on later kindles.  The actual loading of the music onto the player is simply a matter of click and drag into the folders.  Too bad there are only about 4 gigs of space on the reader, but keep in mind that books tend to take up less space.   The biggest flaw in the kindle besides its inherent purpose of being a visual rather than audio device is the interface.  Much like the original iPod shuffle, the built in player does not display track, length, or even shows any signs that it is in fact playing any music at all.  The actual interface only allows for the music to be stopped, or skip ahead to the next track.  The built in speakers are not much to write about, but the sound quality was a pleasant experience considered my actual expectations.  They were able to drive my Sennheiser HD598s to a satisfying degree.  
 
Wrap up: Yes this was a rather whimsical review, but written with a totally straight face.  Overall the built in player on for the Kindle is a pleasant surprise mainly for it's sound quality, though the actual interface is minimal to a flaw.  Will this replace any other source? No.  Can it be used as a substitute if you ever forget your music player?  Sure... why not. 
 
Value: It's a free extra with the reader.
Audio Quality: Decent considering the actual purpose of the device. 
Design: Clever kindle design... No audio interface on keyboard.
Battery Life: Haven't tried to listen till battery death, but should last a time.
User Interface: Minimal to a fault. 

This could be the perfect starter audiophile headphone for anyone looking to get into the game.  Quite possibly the most comfortable headphones I've ever worn.  Darn good highs, mids, and bass though some might find it a bit on the light side.  Overall a great purchase.  Biggest turn of for most will probably be the odd color scheme adopted for the 598, but personally I love it.  Another minor problem is that these headphones do not do metal justice.  Sure they might be great all-rounders, but if metal is the only thing you listen to it would do you good to look at other similarly priced headphones.  Granted these headphones ARE capable of keeping up with most metal bands out there. 
 
EDIT:  To add a bit more to this review.  These headphones are very non-fatiguing.  I've listened to these for hours at a time with no ill effects.  The sound along with the amazingly comfortable ear pads conspire to make these permanently attached to your head for a long time indeed.  I did pay the full 240+ dollars, but with a bit of looking around you can probably buy them for far less.  Although an amp is not needed the HD598's do sound better with an amp.
 
EDIT 2:  These headphones tend to play better with slower music.  Prog rock like Pink Floyd, S.B.B sound fantastic on these headphones, as well as King Crimson.  I've found that bands like the early Black Sabbath, Led Zeppelin, and Deep Purple also sounds very nice.  I've found that dubstep tends to be a bit cold on these headphones, but the bass is there.  I can say that the headphones do sound better after a burn in.
 
EDIT 3:  Nearly a year later, and I still have no issues with these cans.  They have in fact taken over as my go to cans for gaming, movie watching, and just chilling.  Although some creaking has shown it's ugly face this only happens when I adjust my headphones.  The dreaded cracking issues has not surfaced on my post recall production headphones.  I believe that Sennheiser has permanently fixed that issue.  Headphones remain clean, and the pads remain uncompacted.
 
EDIT 4:  Still going at it.  The excellence just keeps coming from these babies.  I can comfortably say that they are now in fact fully burned in.  Soundstage is pretty damn impressive now that I've expanded my collection to more than just two headphones.  Just a few things to note that I haven't really answered before.  
-Bass: Nice thump to it.  Not going to be the tooth filling rattling bass found in my HFI-580, but it does strike a nice balance for me. Give the bass guitar in some older music a nice notable presence.
-Mids: All there and accounted for.  Rather mid-centric in this regard.  Does vocals very well as well as acoustic guitar.  Not too much else to say.  They simply make this can a good fit for most music.
-Highs:  Not too fatiguing at all.  You catch the high bits well enough without feeling like someone just ran a dog whistle through an air compressor. Maybe not as prominent as the mids, but certainly there.
Overall all the bits are there and accounted for.  This headphone from the few I've heard over the years strikes an excellent balance which leave me with the impression that it's current place in the head-ranking is well deserved. (10/28/12)

Bear with me on this review.  The mini disc player for those who don't know was another Sony hard media that failed to take hold (very much like beta) and was killed of in the early 2000s.  The player although small and bullet-proof, it still required a small disc on which to store music.  The diskette was about the size of a PSP UMD cartridge and was capable of holding a few hours of music with the proprietary ATRAC format created and used only by sony products.  Even though I was required to use Sony's own programs to covert my music over to ATRAC I noticed no lack of sound quality.  The design of the player was utilitarian and rather blocky, which might have been a turn of for many.  The battery life came from a single double A battery that was capable of lasting a few days of non-stop play time.  The player's biggest draw back ended up being a rather small display that did not light up, coupled with a slightly vague button setup.  To sum up this player:  It was too little to late.  A great product that was not only overshadowed, but crushed by the Ipod.