As to the newest FW update for the MT... I missed the 2.18 update apparently, and went straight from 2.17 to 2.19. I can tell you now that even though I hadn't heard these in a while, the sound sig has definitely changed. They can indeed get shouty a bit now with certain tracks. It is in the upper mids/lower treble that they boosted it most IMO. It makes the whole treble have more sparkle and clearer. I think the upper treble is still rolled off. So I think maybe you could think of it as a backwards (small) r shape, starting with upper mids and into the treble. These can definitely get shouty on stuff like Motorhead - Ace Of Spades but the treble now sounds a bit weird, thin, and recessed also. But, even when a song isn't shouty (per se'), it is pretty fatiguing after a bit (to my ears). But, my old ears have a 2k to 5k radar for such boosts... 
As for bass, they decreased the mid bass, and boosted the lower bass and possibly the upper bass. They still have a tremendous amount of bass quantity, but now they don't have the same punch they used to have, and that kinda' messes up the whole sound signature IMO. Was just listening to Whitesnake - Death Disco while I was typing this, and WOW that upper bass is just too much (I don't recall this being an issue before, though it IS possible that I missed it before I suppose).
Mids are still recessed a bit, but are also still warm. Overall, I don't like the way they went with it. I was perfectly happy with the tuning on the FW update before the 2.17 update. The punchy bass, and non-shouty mids are part of what gave them their charm IMO, because now, they aren't neutral, nor are they really fun either. CA, if you are reading this, please go back to the sound they had before this rash of updates, and leave them alone (as far as FR goes)?!
Keep in mind, I could be wrong about all except upper bass, and upper mids, because when you boost one area, it may appear as if something else is decreased. They ARE indeed shouty now, and the bass line (not drums) takes front stage in your face.
With the 2.19 update they re-fixed the volume thing where you couldn't change the volume on the device but ONLY on the buds (whether you had absolute volume disabled or not).
I upated mine through my DX300, and it went without hitch (again), and only took about 5 minutes or so.

As for bass, they decreased the mid bass, and boosted the lower bass and possibly the upper bass. They still have a tremendous amount of bass quantity, but now they don't have the same punch they used to have, and that kinda' messes up the whole sound signature IMO. Was just listening to Whitesnake - Death Disco while I was typing this, and WOW that upper bass is just too much (I don't recall this being an issue before, though it IS possible that I missed it before I suppose).
Mids are still recessed a bit, but are also still warm. Overall, I don't like the way they went with it. I was perfectly happy with the tuning on the FW update before the 2.17 update. The punchy bass, and non-shouty mids are part of what gave them their charm IMO, because now, they aren't neutral, nor are they really fun either. CA, if you are reading this, please go back to the sound they had before this rash of updates, and leave them alone (as far as FR goes)?!
Keep in mind, I could be wrong about all except upper bass, and upper mids, because when you boost one area, it may appear as if something else is decreased. They ARE indeed shouty now, and the bass line (not drums) takes front stage in your face.
With the 2.19 update they re-fixed the volume thing where you couldn't change the volume on the device but ONLY on the buds (whether you had absolute volume disabled or not).
I upated mine through my DX300, and it went without hitch (again), and only took about 5 minutes or so.