Over the last couple years, I've been progressively engraving podcasts and audiobooks into my daily routine. Don't know how I ever managed to get along without them. It recently became clear that the time for Apple's earbuds was up. In consequence of that, I started researching for some worthy headphones for my iPhone 4. Since I'm a sucker for wireless and mobility, bluetooth connectivity presented itself as an early must. Nonetheless, because the whole point was to enhance and refine the audio listening experience, I feared that bluetooth bandwidth limitations would seriously undermine sound quality. Those fears were scattered by this post which underlines that, with a practical data transfer of 2.1 Mbit/s, "Bluetooth 2.1 + EDR" has more than enough bandwidth to effortlessly stream CD quality audio. Read several other forum threads on the wildly controversial "wireless vs wired" topic. The bottom line from that was that "wired" headphones will always give you better sound quality, although, for the non-audiophile casual listener, current bluetooth technology should to the trick. Besides bluetooth, I also envisioned the following set of features for my top-notch headphones: -> Circumaural style of wearing (speaker covers the entire ear) + stero: I've read solid reports that supra-aural headphones, unlike circumaural, tend to cause "ear fatigue" after a couple hours of use. -> Noise cancelling system: I often do my listening in the midst of noisy public transport commutes and clamorous vacuum cleaners. Noise cancelling would avoid having to pump up the volume to deafening levels. -> Hands-free calling: despite not being part of my original brainstorm, it gradually became apparent that hands-free calling would be a pretty nice add-on to have. After several hours of unyielding research, I finally managed to boil it down to the following list: Sennheiser MM 550 Travel, Sennheiser MM 450 Travel, Sennheiser MM 400, Sennheiser PXC 360 BT, Sennheiser PXC 310 BT and Sennheiser PX 210 BT. All the previous models can be elegantly collapsable for easier transportation, all have the insightful option to connect through a 3.5mm audio cable, and a couple incorporate the creative "TalkThrough" feature. From the above list, only two are circumaural: Sennheiser MM 550 Travel and Sennheiser PXC 360 BT. The former allows for "hands-free calling" but has no "apt-X®" support, whilst the later boasts "apt-X®" support but has no "hands-free calling". Either one is outrageously expensive. Taking into account my features list, does anyone know of another model I should be considering? If not, is there any mate out there with hands-on experience on the two above circumaural models? If so, does the "apt-X®" feature really makes that much of a difference in sound quality? Is the "hands-free calling" worth it? Which one would you advise? Thanks in advance!