Pros: realism, speed, clarity, musicality, frequency response and extensions, tonality, details, instruments separation and positioning
Cons: bass weight
Disclaimer: I've got my RE272 as a review sample for free.
There are more pros and cons in my full review, like
- Soundstage size is good for IEM, but I like to have more.
But this is just a nitpicking, and I do not consider this as a real "negative aspects" (this is how cons are defined here in Reviews section). I rather call this "wishes".
Conclusion: I prefer RE272 over any IEM I tried.
Tried, in order of preference (not just SQ): RE262, RE252, RE0, ER-4P/S, MTPC, E500 (SE535), RE-Zero, CK10, SA6, ER-6i, E4c (wow, this is ancient!), UM2, some more. Note: order may change depending on the source.
Similarity: RE272 sounds like ER-4P reincarnated into dynamic driver version. And it turns out to be a step up over ER-4P, rather than a side steps presented by former HiFiMan models.