What are the most important features to look for in wireless headphones/earphones?

[Android Optimizer]

There are quite a few options out there when it comes go Bluetooth wireless headphones/earphones. What are key features to be looking for when shopping for headsets/headphones/earphones?

Some of the features out there are:

APT-X (rumored not to compress sound, and give better quailty sound - does it?)
Noise canceling (CVC 6.0 - said to keep out outside noise - does it? Some sets have dual microphones that are supposed to take outside noise and filter out those sounds internally - do they?)
how well it stays in/on ear (there is over the ear, ear hooks, different size buds - what works and what doesn't? What's comfortable, and what isn't?)
listening time (how long the battery lasts on a charge. How much is enough, and how much is too little in your experiences?)
how long it takes to charge
(I'm probably missing a few others)

What are important features to look for, and what are just buzz words and hype that don't matter?

 

[LeoRex]

Well... from my perspective in order of importance.

1) Fit/comfort - if the damn things don't fit right, hurt after wearing for a few minutes, fall out easy... that renders them more useless than most anything else...
2) Sound quality - I've had a bunch of ear buds and if the sound quality is trash, or the volume levels are junk... again... you'll never want to use them and look for a replacement
3) listening time - if the best fitting and sounding buds only last 45 minutes... meh...

As for noise canceling... most in-ear buds have some level of passive noise cancellation because they're stuffed in your ear. Now, active noise cancellation is the most ideal BUT... buds that have it are often crazy expensive and it will have an impact on charge performance since its more stuff the buds have to do. Plus, it will add a little bit of mass and size... Provided they don't transfer a ton of wind noise, I wouldn't concern myself with active NC unless you positively have to have it.