Swapped the flat pads to the Alessandro MS-1 and surprise, surprise, they sound better than the comfy pads. I do have to turn the volume down a bit with the drivers firing directly into my ears. I may have been wrong about the deluxe flat pads feeling denser – that might have been normal manufacturing variance. The regular flat pads on the MS-1 hurt my ears after about 2 hours, since they have the stock Grado ear-crushing clamp. The pain I endure for dat bass.
I tried the flats on the MS-1 when I first got the flats, but they never got a fair chance because the flats were going on the HP 2. The comfy pads tend to cut a bit of the treble and transparency (transients, attack speed, decay, etc.), but I guess I was in denial, not wanting to buy another pair of flats back then. Win-win today.
There is a spare pair of bowl pads sitting around my place somewhere (not crumbling). I'm not sure what John Grado does to the drivers, etc. to voice them for bowl and bagel pads, but you'd think there would be some major changes to sculpt the bass and to avoid a midrange-treble suckout with the additional volume around your ears. I wasn't a fan of the bowls as the treble reverberations sounded fake with my HP 2 and MS-1 and bass quality and quantity were dramatically reduced.