First, an admission of bias: I love Shure. I had a pair of Shure's E3c noise-isolating headphones for two years, and boy did I adore them. Great loud or soft, comfortable, able to make a transcontinental jet flight whisper-quiet while listening to jazz one tick above mute--bliss. I think I blew out one of the drivers before running them over with my bike, but I didn't mind. Bygones. So I was ripe with anticipation when Shure shared their SE310 headphones (as well as their top-line model, which I have not reviewed yet). Could these be the replacement I'd been seeking? My heart got heavy when I discovered the truth: I don't love the SE310s. What's wrong with me? I want to love the Shures. I want to recapture my lost joy.The difference, I think, is in the level of headphones. The SE310s are $299 headphones, and are playing in a different arena in many ways than my old E3cs, which, if memory serves, retailed for $199 and cost significantly less. At this price range--which I've experienced with several brands--headphones start becoming reference-grade, where the focus of the output is on re-creating the original sound more than just making stuff sound great. (I unearthed this trend on the Etymotic hf2 when I began this review series.) When I plugged the headphones into my home stereo, I heard Shure's solid headphone output: separation of instruments, a focus on high-end clarity, strength across the audible range. Tonal separation holds its own against the hf2. But my typical listening scenario--out of the home, at low levels--turned out to be less than ideal for these headphones. In that environment, the midrange lacks warmth and depth, and the acoustics flatten significantly. I was startled, but a bit of research revealed similar complaints on old reviews of Shure's E4c headphones elsewhere online. Unlike my old E3cs, richness and bass reproduction aren't Shure's strong suit at this level. That's a shame, because the SE310s are fantastic noise isolators. On the commute to work, I had a consistently quiet ride, making it easy to listen to music safely. The Shures by far have the best scores I've given for noise reduction. They're an inverse of the Klipsch Image X5, which had midrange and low-end richness but weak noise isolation (if you'll recall, I stuck some Shure foam ear cushions on the X5s as part of my testing). So I guess the SE310s aren't for me. I still have every expectation of loving Shure's SE530s, which are in the queue (and at $549 the most expensive headphones I've ever encountered). In the meantime, I've learned something: my audiophile nature has its limits.