I've been lurking and reading various threads, and it seems that at the higher end there is no consensus on a 'best' IEM. Much of it seems to come down to personal preference and the sound signature that appeals to each individual. Still, I'm going to ask for some thoughts, and try and provide some information to help! I've been using a set of Shure SE425s for the past 3 years with the tri-flange earbuds trimmed down. I've never really found this fatiguing as a few users have suggested. Indeed I've often described this as one of the best purchases I've ever made, which gives me a degree of confidence to now look towards higher end models. When I originally bought the 425s I found I much preferred the 215s over the 315s, the latter felt 'muffled' to me, like they sacrified clarity to get a more bass driven sound, more like the Bose IEs. The 425s with dual driver seemed like the ideal solution and I've been very happy with that choice. The cable now needs replacing which has prompted to me to review other options. Perhaps worth noting that at least 90% of what I listen to is female vocalists, maybe 8% instrumental/classic and at most 1% with male vocalists. Right now I'm quite in love with Norah Jones on Tidal's 'master quality'. Taylor Swift is probably as pop as I get, could listen to the likes of Shania Twain and Carrie Underwood for hours. Give me some Katherine Jenkins, Leona Lewis, my long standing love Delta Goodrem. The 'heaviest' I've got is Evanescence and nothing towards the rap or electronic genres. Given I've got a fairly finite preference I'm hoping there may be an IEM that stands out as being ideal. A few models come to mind, the 535(LTD), 846s, Westone W60/W80, and the Sennheiser IE800s. Unfortunately I've not been able to actually listen to any of these. I'm not entirely convinced about the 535s as an upgrade over the 425s or the value proposition for the LTD version. I'm leaning towards the 846s given I've greatly enjoyed the 425s and the mid-centric Shure style, but I have no exposure to others like Westone for comparison. Most of my listening is simply at the computer or phone through Tidal or lossless rips, no amp, no dac (though I'm somewhat open to improvements here too). Honestly I'm not really qualified to talk of the technicalities of sound. At best I can say vs the 425s I'm looking for a slightly 'richer' sound and bigger soundstage, more of a bass response but not at the expense of clarity in the mids and higher end. All I can truly speak to is the enjoyment - when I bought the 425s I remember smiling and saying "hey, music is actually a pleasure listen to now". I'm hoping to discover another level of that experience! If you've made it this far, congratulations, and thanks for reading.