Sorry for the double post here, but A) I'm going to do it anyway and B) I just have to rave.
I'm still using my W80s multiple years later, and barring some paint flaking on the J-clips (which I'm going to replace for metal ones at some point) they are still in prime condition and still sound as good as ever.
They sound so good, in fact, that I have a ridiculous number of hours on them, and to this day I still regularly wear them, logging many hours per week just listening to phat beats.
I have discovered that I like the red (huge) eartips the most, but I've also discovered that the bloated (but not muddy) mid-bass that was fatiguing my ears and brain is actually a result of this exceptional fit and disturbingly deep insertion into my cavernous ear canals. Turns out, if I a push the eartips in, but stop immediately upon getting a seal, and push no further, then I will get not only clear, robust bass from bottom end to top, but the mids and highs will also open up.
Try this: Take your hands and cup them BEHIND your ears, so that your palms are gently pushing your ear flanges forward. Notice that immediately you start hearing a kind of whooshing, hissing treble. This is essentially what happens when the eartips are sealed fully but at a shallow depth. You get all the sound, but now the treble and mids are lifted, though not as dramatically as my ear-cupping analogy.
Some people have said that the subbass is not sufficient, but these bad boys go down to 5hz (!!!!!!!!!!) and having listened to plenty of bassy music, I believe it. They are MONSTERS when it comes to bass, utterly refined, cleared and powerful. I think the problem, assuming that these people are getting a proper seal, is that they want exaggerated bass.
The W80s are not club-IEMs, they are gentlemen at the driving range. Casual, enjoying friendly banter, and then, with a careful wind-up, launch the ball with controlled strength. Nothing wasted.
So when bass hits lightly, these hit lightly. When bass hits hard, these bring the thunder. So if you want to hear subbass over the other instruments when that's not what the track calls for, then the W80s will politely decline: They're here for accuracy, not embellishments, and I believe the story is just as good when all the details presented are of sound veracity.
I love these IEMs, and if mine go bottom-uppers then I will buy another pair, which I can now get for a paltry $400. Unless I get very curious about the Mach80s, but frankly, I don't like their new design. Their old design is plain, but the new design is generic, which I believe is worse.
So that's what I have to say. Get a good fit, find the right depth, determine the best tips, and if you want more bass, stop listening to power metal and classical and start listening to music that contains "drops," ideally anything that says "Bass boost +10db bass test boosted WILL DESTROY SPEAKERS."
You should get your fix.