Joker mentioned somewhere that his J3 is sufficient enough to drive the RE262, though I forgot where, so I can't quote his post. He also mentioned that Fiio E5 is more of a toy bass boost rather than an amplifier.
The MeElectronics M6 is NOT are not earbuds. They are noise-isolating IEM's. And the MeElec M6 is low below your $60 budget. You can get definitely get something better at that price, but if you're looking for just using it in the gym, I think the M6 will be sufficient.
I am currently in possession of the DN-19 and reviewing it as we speak.
Expect a review in this few coming weeks!
Bass is indeed enhanced A LOT with the screw-able damper off, pointing to "bassy"
With the damper on however, it gets much more balanced, but the bass still has a lot of punch.
One thing I notice is that Micro Details is very easy to catch with this IEM.
That's all for now!
I'm sorry if I didn't read your post, I will try to find it. It's hard to imagine the FXD80 trumps the FXT90 though... From the price point, the FXT90 is still more expensive right? Correct me if I'm wrong
You can look at Joker's Build Quality Rating for the RE272. From the looks of it, it's not badly built at all. IMO the E9 will actually be overkill. I don't know about the RE262, but sometimes I can't even use my Fiio E11 with my very sensitive IEM's. Even at the lowest volumes they're still too loud, and when I go even lower, the dreaded channel imbalance prevents me from hearing my music.