Well, if it's of any use to you.
I have been using the clear UM2s for quite sometime now. Simply love them, and they are just too comfy!
Recently i headed down to audition a pair of SM3s and TF10s, well, like some have mentioned, the SM3s signature takes some getting use to.
Its pretty dark, but overall somewhat similar to the UM2(well, just barely).
I probably need more time with them to find out their full potential.
Well, to cut it short, i settled on a pair of TF10s to reshell. Cldn't beat the price.
The TF10 handled the highs quite alot better, without being grainy or harsh. Its alot brighter sounding than the SM3.
BUT, the bass emphasis isn't as apparent when compared to the UM2 of course, that was pretty obvious. But it did feel more punchy and precise.
Apologise if i just made your paradox of choices, more "paradox-ical".
My $0.02.
Thanx!