I'm glad you brought that up Boombox - not only for music lovers but for dx'ers as well when it comes to these "on-ear" rather than the IEM, or "in the ear canal" monitors.
I can't speak for the Sony's, but I can speak for the Sennheisers - 99% of the population don't know how to wear them right, or how important the little foam pad is!
The Sennheiser 365's are known to have big drivers in the first place. Add to that the pads, and some people are just in pain now.
PADS - they are a critical part of the system design, not just for comfort but also for frequency response, and it falls into two categories:
1) The frequency response, as designed from the factory is with the pads ON. Just like you don't wear larger over-the-ear, or on-the-ear head-clamping headphones without pads or earcups, neither should you go without on the buds. Measurements on laboratory dummy-heads proves this out with the sponge on and sponge off graphs showing a wide disparity and the design is that for the pads being on.
Now the previously "thin" sound of the 365's grow with the proper amount of bass and midrange clarity. This means you don't have to drive them as loud to compensate, which can muddy sound, or do overdrive damage eventually. Also, the highs are no longer so strident, but more detailed. Because these are on-ear buds, and not in-the-canal IEM types, that added bass and midrange is well under control, not boomy or monotonous, but detailed. (dx'ers are yawning already.)
This means you can truly enjoy hi-fi, or pull out that weak station ID when dx'ing.
2) Improper wear - even with the 365's larger driver, and made even larger with the pads, most wear them the wrong way. Just like you shouldn't have to mash studio monitors into your head with your hands, neither do you have to get lobe-smashingly tight with these. The pads again are key.
Just a gentle nudge into your ears, but not fully down next to the canal is all it takes. The slight amount of pad friction hold them in place, without having to be "inside" your ear so to speak. Just against something in your ear enough not to fall out by force of gravity and a little bit of pad friction. Thus you can actually accommodate larger drivers.
Ironically, if one is wearing them properly, then they *should* fall out on occasion, or need a slight tweak now and then. It's a small price to pay for that kind of comfort, and most importantly, fidelity.
But, many think of these as jogging or work-out phones. They are not. But they are commonly put to that use by not wearing the pads, and trying to jam them way down low for some sort of really snug hook-my-canal fit. They are NOT meant to be snug, but just barely hanging in there with a tiny amound of pad friction. The drivers don't have to be perfectly centered over the canal - just a gentle tap is all that is needed. One doesn't have to try and emulate an IEM canal type by perfectly centering the drivers outside the canals.
This is one reason you can barely trust ANY online reviews, because the vast majority of people don't use the pads - or those that do try to smash the whole package all the way in. In the end, I believe this is part of the reason that this type of earbud is so hard to find - the manufacturer's don't include instructions, and some don't even realize that the drivers are keyed to left and right ears individually in some cases, like this model.
"Ow, these things hurt, they fall out, and they sound tinny! - do not buy" is the common refrain. Yes, some ears are just too small, but I'll bet that if taught to wear them properly, many of the smaller ears would do just fine without pain.
Maybe I put the graph measurements to the link for these in the other thread on the Skywave. I'll have to check. Ah, here it is - a few charts down show the sponge-on and sponge-off response. Because these are on-ear, and not IEM's, don't initially get too freaked out at the improved response down low:
http://en.goldenears.net/25818
But thanks again for bringing this up, as this style of earbud, in a high-fidelity version at least, is getting harder and harder to find.