My girlfriend was gifted a pair of RE-272s (what a gift!), but she didn't like them as she did not like waring them over the ear and straight down was not performing well enough.
So I am using them ...
And I must say, the ear tips are atrocious! I saw a lot of people complaining about lack of bass but I think they were using the provided ear tips, which suck (for me at least). I swapped them for Sony Hybrid tips that I had lying around (M and L work for me) ... and WOW. The bass isn't "boomy" but it definitely comes alive!
These are the best sounding IEMs I have ever used. Just thought I would share that. I love Sony Hybrid tips