Sound quality of the Samson Z35 is superb. Clean and flat sound signature, but powerful, fairly deep bass extension, crystal clear mid-highs, very clean, well-defined sparkling treble. No spikes, no surprises anywhere. Very real presence and convincing sound stage. 
 
Fit is very comfortable, real leather ear cushions, which do not get hot & sweaty at all (so far - been listening to ambient/trance on and off for a few days). Initial head clamp force is fairly high, but loosens up after a few days of listening. Inner head band is soft, pliant cushioned material, with "samson" logo printed on top. 
 
Very efficient, 40 mm 32 ohm drivers, so they crank. They do not break up or lose coherence at all, at high sound levels.

High grade, durable materials, fit & construction - albeit all black plastic.Tasteful, "smoked" chrome accents. These cans are very light and portable - ear cups swivel and fold up into a nice, tight bundle. Not much to look at, visually, but these headphones are very deceptive, because they deliver so much, sonically. Includes 1/8" - 1/4" gold adapter and black pleather travel pouch. Samson 2 year warranty.

Samson sent these to me free of charge, to replace my SR950s, which developed shorts in the cord and plug (SR950s were fairly decent-sounding budget cans, and a bargain off Amazon at $42) The Samson Z35s are going for $69.99 USD on Amazon.com. The SR950s had more "fun factor" than their older SR850 sibling, with boosted low bass and upper treble, but I found their audio signature a bit heavy and uninvolving after extended listening. These newer Z35s trounce them in just about every department.

At this price point, the Z35's also compare quite favorably to the Sennheiser HD280 Pros (not saying much, imho), which I found to be very bland and vapid-sounding (and somewhat overpriced at $99.99).  The HD280s were very uncomfortable to me, right out of the box (pleather ear cushions were unyielding, too shallow, leading to outer ear pain, hot/sweaty, and head clamping force was atrocious and unrelenting).
 
I am enjoying these Z35's the more I listen to them. They just provide an excellent, all-around engaging listen, and with more than adequate detail, they deliver the goods. 
 
 
Samson Z35 Stuidio Headphones Specs:
 
TYPE: Over-ear, closed back dynamic (40mm)
SENSITIVITY (@1kHz) db/W: 94 dB
MAX INPUT POWER @1kHz: 500mW
FREQUENCY RESPONSE: 20Hz - 20kHz
IMPEDANCE: 32 ohms

They just work. Nice, clear & flat-sounding (nothing in audio spectrum particularly stands out -  a good thing, if you want to approach "analytical", which these things most assuredly are not).  Listening to 320 kbps ambient tracks on internet-radio.com right now.  Very immersive, good sound stage / separation.
 
Very Comfy fit, using large silicone tips. No cable noise. Decent build quality.
 
Excellent bargain at Amazon.com - $9.45 USD.  What's not to like?
 
These things garner 4.4 out of 5 stars among 38,316 reviews on Amazon.com, which has to count for something, I would think. I agree; I'm giving these 4.5 stars.

These are just plain excellent.  I was never really a believer in IEMs, but I am now. These Philips SHE3590s are a real eye-opener.  According to the ratings here on Head-Fi, these do, in fact, out-perform some of the $400+ kit...and I am not surprised.  The main complaint regarding sound quality seems to be a slight lack of clear, natural highs/treble (kind of artificial-sounding). I agree somewhat, and I experimented with my laptop's B&O equalizer by rolling back the Philips' 4 KHz and 8 KHz regions down to -2 and -3 db respectively, and boosting the 16 KHz region to +3db. They now indeed sparkle, without sounding artificial at all. Bass is very clear, deep and punchy; does not need any EQ at all. Mids are clear and well-defined. Cable is rugged & constructed of good material, but does make a lot of noise when hanging straight down. I looped the leads over my ears - end of problem. Isolation is great.  At $16.95 at the local CVS pharmacy, these are a very good value.   5 stars * * * * *
 
- Trev

Just got these, and right off the bat they're very impressive.
 
Full, clear sound, plenty of energy & balance throughout the entire audio spectrum, with slight humps in the 20 - 100 Hz region (+3.5 dB) and from 6 KHz on up to 14 KHz (also around +3.5 dB). I flattened these right out with Peter Verbeek's excellent APO EQ system. Everything sounds very natural and clean. Sound stage is also very well delineated - especially for a completely closed design like this. Isolation also very good.
 
50 mm drivers, neodymium magnets, 10 Hz - 25 KHz frequency response, +/- 5 dB
 
Sensitivity is 96 dB/mW, and the impedance is 32 Ohms, so they're easily driven.
 
I am just floored in a good way at the sonic qualities of these things, especially given the $38 USD I paid for them (new).
 
Velour ear pads very comfortable.
 
Aesthetically, they're just flat-out ugly to look at, but I knew that before I bought them.  They just sound great, and are very comfortable.
 
Very immersive; I found myself drawn right into the music, as opposed to just listening to the headphones themselves. Ideally, for the best experience of musical reproduction, audio transducers (whether headphones or speakers) should disappear (or should become utterly "transparent"), so that only the music remains.  These headphones accomplish just that; they get out of the way and they let the music take over.
 
Clamping force on the head is a bit tight, but they're brand new, and I'm sure they'll break in nicely. I stretched them out overnight, using the Samson box they came in.
 
I've included an image of Samson's original OEM spectrum trace ("SR950_FreqTrace.jpg"), along with an image of the EQ-corrected humps, using the APO equalizer ("SR950_APO_1_sm.jpg")
 
UPDATE:  I just listened to Bruce Cockburn's "You Get Bigger as you Go" at 1080p right here:  https://www.youtube.com/watch?v=wefFe9zlXTQ  -   in my experience, this is probably the highest quality audio recording in all of YouTube. When this is played at 1080p resolution, the sound quality through these SR-950s is nothing short of breathtaking.  The harmonics and overtones of the guitar literally sparkle - without being sibilant, and with no hint of breakup - the brass of the cymbals sizzles, and the toms and kick drum slam and thump hard and deep.  Amazing results with just a modest amount of EQ.  So glad I got these....really enjoying them.
 
 
  
 
  

Transformative, in a big and positive way.  The perfect, finishing touch on my Panasonic RP-HTF600-S phones...makes them look almost high-end, and they certainly approach it, in sound.  Most impressive.
 
Was skeptical about all the hype surrounding these velour pads, but now I get it. I really do. Amazing audio improvements, and hours on end comfort.
 
I'm even going out on a limb here...but it's the truth:  I heard some of the reviewers here say that these Panasonic RP-HTF600-S phones are so good that they gave them chills, and almost made them weep while listening to some material. I experienced chills myself, when I first got these phones and took a listen...and about a week later, after I installed these Beyerdynamics, I can say without hyperbole that I've been repeatedly and very nearly brought to tears several times while listening to some 320 kbps streaming ambient music with these cans, equipped with the Byerdynamic velour pads installed.
 
5 Stars *****

Bought these last week off Amazon.com for $34.  Right out of the box they sounded great to me.
 
Was never a believer in "burn-in", but now it makes sense;  headphones have drivers, which are essentially air-moving diaphragms mounted on pistons (voice coils) - and it is completely reasonable to suppose that these diaphragms get conditioned after so many excursions & hours of flexing and use. Anyway, after about 40 hours of listening, these phones sweetened up quite a bit.
 
Then I got the Byerdynamic ear pads today ($25 USD off Amazon) and installed them - signature-wise, mids are a bit more clear, and the treble really came to life and really does sparkle.  The bottom end of these phones is still just as massive, deep and impressive.
 
Using my funny audiophile synergistic math, $34 + $25 = $250 - grade headphones...proving once again the old adage that the whole is more than the sum of its parts.
 
5 stars *****