...especially since the 6i is NOT a model number used by Shure. It is however a model number used by Etymotic. Ouch; didn't know what you bought?
Helps to get your story straight to establish ANY credibility with anything else you have to say.
As for any inability to spend serious presidents on earphones...get real. Just like full-sized speakers, a good set of cans is critical to getting a great sound. I do agree that Senn's PX100 is an exceptional-sounding headphone design; they have an excellent, open sound straight out of the box that just mellows and becomes velvety smooth with usage and break-in.
But it's not like they don't have drawbacks. They have a large form-factor compared to any set of buds or canals, meaning that for many they're far more of a hassle to haul around. Discrete usage isn't an option, unless you have long hair. And their open design means that they don't isolate; intrusive ambient sounds are easy to hear and your own listening material played through them at higher levels is VERY public as well. Chances are that the typical bud/canal user isn't interested in over-ear cans for one if not all of those reasons.
Back to the subject at hand that started this thread...as for in-ear monitors; I agree with Sanjay's post on the branch below. There are in-ears and then there are IN-EARS. Guttenberg's review of the Klipsch Image would make me pass, regardless of how they thump on the low end. Sound has to be balanced, and while Etys aren't very good at reproducing low frequencies with any sort of oomph, their other virtues with mid and upper range detail and precision are highly valued by me. Which is why I'd recommend the Shure SE530 over the Image. When it comes to canals that I've used, I truly CAN'T live without my E500/SE530 set; stepping back to lessor designs is a serious backwards step. They are an excellent compromise between detail and bass. And no, I don't have a problem paying more for them than I did my iPod or Zune, just like I've never had a problem paying more for speakers than any of my electronics, home and mobile; you don't skimp on your output devices, PERIOD, because those do the most in impacting what you'll hear. As important as having a good amp is (and it IS important in getting the best possible sound, even for headphones), the speaker driver imparts its virtues (and flaws) more forcefully than any nuances that an amplifier will ever do.
Mr. Miyagi, I have found balance. Might work for Daniel-san as well.
When the right ear housing of my cherished E500 set broke (the housing snapped at the thin trumpet that connects the main body to the in-ear tip), the downtime when I sent it back to Shure was simply intolerable. I used my Super.fi 5 Pros and V-moda Vibe (another bass-heavy design) and couldn't wait for my replacements to arrive. The SE530 Shure sent back (virtually identical to the E500 except for the model number and a number of different tip designs they supply with the unit) was like reliving fond memories with a long-lost old friend; it's that good. Doesn't matter if the source material is compressed; there's no comparison, even against my well-broken in, silky-sounding PX100 set that I also cherish and will NEVER AGAIN take out of the house because of how long it took to break this set in to achieve their current level of smoothness).
In straight up sonic comparisons with traditional over-ear sets, I admit I'd choose a good over-ear design over the Shure set, but I'd also NEVER haul around my Senn HD650s and amp with my MP3 player. The Shures do take a big bite out of the charge card, but once you've heard them, you're hooked for life.
Or at least until the next super canal set comes along.