If you're the type who likes to play around with the sound settings of your music -- and I suspect that a lot of folks who buy these headphones will be that type -- the app will be fun to play around with. If you're not, it will seem like more of a nuisance. It also limits you a bit if you don't have an iOS- or Android-based device. Yes, you should be able to use this with any Bluetooth-enabled device, including a laptop, but you won't be able to turn off the noise cancellation or make other sound adjustments.
The Ziks' performance is little bit hard to judge because their performance encompasses more than just sound quality. However, one thing that can be said for certain is that these sound excellent for Bluetooth headphones; they're among the best I've heard. The only problem is that because they're such capable headphones, they tend to make badly recorded or compressed music sound worse. When I was listening to lossless material, they sounded great. With lots of detail and good, tight bass, they're well-balanced and have an audio profile that will appeal to audiophiles. (No, they don't overemphasize the bass, so if you're a bass lover, these will probably fall a little short for you.)
When I turned to Spotify, the listening experience became more hit or miss. Some tracks sounded really good while others exhibited a harsher edge, and the flaws in the tracks were accentuated.
I played around with the EQ settings and disengaged the default Concert Hall effect, then turned it back on. I also turned off the noise cancellation, which works quite well when activated; it's among the better noise-cancellation experiences I've encountered. None of this made a huge difference in sound quality, for the better, anyway, but people have such different sound tastes, and this makes it possible to adjust things so they're more to your individual liking.
One thing that surprised me a bit was that using the Ziks as wired headphones really didn't improve the sound. You'd think it would, but with all the digital processing going on, it seems to be better to stick to listening to these in wireless mode.
Since the headphones do passively seal out a lot of noise, you may want to disengage the noise canceling. When the music was off or between tracks, I did hear a faint hiss, which is par for the course for noise cancellation, and went away when I turned the noise canceling off.
Wearing the headphones, I made a few calls, and while I thought the Ziks worked pretty well as a headset I expected a little more. I could hear the people I spoke fine, but they said I sounded a little grainy and muffled and that it sounded like the microphone wasn't that close to my mouth.
As for battery life, it's pretty decent, though not great. You get about 6 hours of power when all the features are activated. If you turn off the Bluetooth and just leave noise-canceling on, you get upward of 18 hours of use before recharging. If the battery dies, you can use the headphones as wired headphones, but you obviously won't be able to use the noise-canceling or Bluetooth features.
As I said at the beginning of this section, it's a bit difficult to asses the Zik headphones' performance because, unlike with other headphones, more than sound quality goes into that performance -- including wireless playback. I must say that I did encounter some glitches during playback. Occasionally, I'd get some brief dropouts, and a few times after leaving the music paused, when I put the headphones back on things got wiggy, with my music starting, then stopping, then starting again. Also, after I upgraded the firmware to version 0.10 via the app, I found the headphones wouldn't turn on. I removed the battery, put it back in, then plugged in the USB charging cable. Eventually, the headphones started back up again and seemed to work OK.
I'm not sure what the 0.10 number on the firmware actually means (typically anything less than 1.0 would indicate the firmware is actually in a beta state), but presumably additional firmware upgrades will make the headphones' operation even more stable.
Overall, I really liked the Zik headphones, though I do have some reservations. As I said, I thought the sound quality was excellent for Bluetooth headphones. I found the Ziks' sound to be detailed and balanced, with a sound profile that will appeal to audiophiles. While the headphones are comfortable, they're a bit heavy, and after longer listening sessions, you may come to find them less comfortable (I think they're better for those with bigger heads).
My other concern is that these headphones don't feel quite fully baked yet. This is more of software issue than a hardware one, but there are definitely some little kinks, call them bugs if you will, that need to be worked out. That said, I do expect the Ziks to improve with time and future firmware upgrades. That's a bit of a strange thing to say about a pair of headphones, but when you have something like the Zik headphones, which incorporate so many digital enhancements and a companion app, you end talking about them like they're a "smart" device rather than a simple set of speakers that you wear on your ears.
The big question, of course, is whether they're worth $400. For most people they won't be. But if you're looking for a pair of wireless Bluetooth headphones that sound really good, have an impressive design, and have some really nifty features (the touch controls in particular) that will make your friends envious, it's easy to make a case for buying these. I just wish they included a better carrying case.
Editors' note (April 30, 2013): The rating of this product has been adjusted slightly higher to reflect this product's position in the competitive marketplace.