My ER2XR has arrived lately. Here is my first thoughts with the tri-flange tips which come attached to iems out of the box: Can't reach TOTL iems level by any means and it's totally normal considering the price tag. Resolution is worse than ER4XR, upper treble rolled off and not enough extension, female vocals is ok, male vocals need to be more clear, good amount of subbass quantity but can't say the same for its control, bloated frankly. After this initial impressions I was seriously considering returning them. Because I liked ER4XR with tri-flange tips rather than foams. How could be different with these? Well, that's a mistake for dynamic drivers, at least for this one apparently. I've been listening to it with foam tips for 3 hours without any fatigue. Foams comparing to stock tri-flanged tips, more dynamism in midrange, no more bloated sub to mid area, midbass quantity meets the quality finally, definitely more clear upper mids and timbre is one of the best you can hear from a dynamic driver iem. A change of tips then viola! Completely different experience for me. At this price tag, ER2XR "with foam tips" is a no brainer. Just my .02 cents.