@phillyd It's been mentioned multiple times already, but I'll just do it again. The SE215 and 425 don't have much in common except for the basic shape and manufacturer. One is very warm, full and bassy, whereas the other is neutral to mid-centric. If you were looking for an upgrade to the SE215 but with a more or less same tonal direction, perhaps with somewhat more treble sparkle and brightness, then the SE425 was one of the worst choices you could have made. Personally, I wouldn't recommend the T20(i) all that much these days - imho the iBasso IT01 does a better job at half the price, however with a more realistic (yet still not 100% perfect) treble compared to the RHA, and the cable quality is superior as well (some users have experienced defects and torn insulation around the ear guides). Or for a treble that is relaxed, just like the SE215's, the EARNiNE EN210 would be a nice option as well. Mentioning the Oriveti Basic doesn't hurt either, however it's more of a sidegrade in my opinion (somewhat softer bass than the Shure, slightly higher details overall).