It may depend on what qualifies as "headphone-like" sound. If what you're looking for is something that's more open-sounding than an IEM, with a wider soundstage and good sound quality, earbuds are certainly worth a look. I have a pair of Venture Electronics Zen 2.0 that I like quite a bit, and there are other high-end earbud offerings from other makers (Shozy, Rose, Yuin), might be worth looking into. The Zen has a wider soundstage than the iSine 20 and does not (for me) require any EQ, although I would not say they sound as good the iSine. If you're curious but don't want to spend much, pick up a pair of VE's Monks and see if the form factor works for you. If you want something that is overall similar to the iSine but doesn't need EQ, the Unique Melody Me.1 is a similar design, a semi-open planar IEM. At $759, they're more than a pair of iSine 20 but still much less than an LCD i4.