Just got a pair of these for Christmas and to my (admittedly classically trained) ears they sound fantastic! You know, I never quite got why people complain about the bass response on these. I'm using the stock 3-flanges and to me they sound wonderfully articulate all over the spectrum with the low end even being a just a hair "woofy" to me even - but then again my usual cans are the AKG K271S and being a classical musician I love me a good, clean, analytical sound.
You might be warned, this definitely could be an issue with IEM insertion for many people - you REALLY have to align the ear canal EXACTLY by pulling up on the pinea and (slowly and gently) push them in a pretty good distance. I mean, I have some medical training and I found the procedure for getting a good seal to be pretty involved but a piece of cake once you teach yourself how. These aren't your crappy Koss pseudo-IEMs....they're gonna feel weird at first as your ear canals aren't used to having stuff in them that deeply, but you'll get used to it soon enough. Once you figure it out with the right ear tip I'm sure you'll be golden. They're wonderful cans.