Well, I've had the RE-272 for about 5 weeks now and I am thrilled with them.
At the risk of repeating what other have said about them, I'll try to keep it short:
1. They were a bit too edgy/snappy for my taste at first but burn in time smoothed them up beautifully. Sounded great after about 150 hrs, excellent after 300 hrs, and plain wonderful now at 500 hrs mark.
2. I was kind of disappointed about the bass but quickly realized finding the right fit is crucial in the bass rendering department. Once I found the optimal insertion/depth with white silicone double flange tips, the bass/sub bass were 10 times improved already. Still a bit shy for me (coming from AH-D7000 and ie80) but the use of the equalizer on Hifiman HM-801 and iphone 4 (with $4.99 Accudio app!) took care of that beautifully. Bass texture and quality is now fantastic to my ears. The whole frequency spectrum is so well balanced and natural.
People seem to point at the treble being the strength of these buds but I think the meds, bass, and sub bass are equality impressive.
When comparing them with the balanced Hifiman with an iphone, I definitely preferred the Hifiman which produced better everything especially better bass weight. However, after installing Accudio pro on my iphone to benefit from an equalizer and better (Flac) files quality, I am quite amazed at how great the RE-272 sound. If not quite up to the balanced Hifiman's standard, it still sounds so good that I rarely use my Hifiman on the go anymore!!! I could totally live with just that.
... Perhaps the nicest surprise was to find out that Re-272 render any recording (older included) very well as opposed to many other earphones/headphones that in my experience, appeared to be very much recording dependent...
Thanks to everyone's contribution that led me to give them a try, I'm sure enjoying them daily!