-Is there something that connects to the controller itself, or do you just sync it to the console like with a wireless controller? If something does connect to the controller, is it any more/less obtrusive than the connector for the wired headset, or about the same (other than the wire itself of course)?
You just sync it like the wireless controller. You can actually use the wireless headset without having the controller on. You also get a battery-life gauge on your dashboard like your wireless controller.
-How does muting work? Is the switch on the actual headset or is it elsewhere? Is it still a slider like the wired headset's mute, or is it a button or something different?
You tap the power button, and hold the power button to turn it on and off. It will beep every 30 seconds to let you know it's muted.
-Is the quality any better or worse than on the wired headset, or is the only advantage being able to move around freely?
The quality is a lot better on the wireless headset (in my opinion). The only downside I've had so far is people complaining that I sound like I'm underwater (ask zewone/jimmiemac since they always bitch at me about it). I've heard other people who have it on and I think it sounds fine, but there is a definitely a difference between the wired/wireless headset. And you have to position it in a certain way to have it pick up your normal talking voice.
-Some Amazon reviews mentioned "improvements" in the Halo 3 headset. While I'm not a huge Halo fan, the branding/color certainly wouldn't bother me, so is there any advantage to getting the Halo 3 headset over the regular white one? It's $13 more expensive on Amazon - is that for any reason other than the brand?
I'm not sure what the improvements were, but I got the halo3 one and I can tell the difference from when someone is using the Halo3 one and the old AC wall adapter headset. I'm not sure about the white USB one though.
-I've read conflicting reports of how the thing charges. Is it an AC adapter, or does it charge via USB? Either way, if it dies/is dying while you're talking, is the cord it uses to charge long enough that in a worst case scenario you can continue to use it while it charges, or is that not possible?
The AC Adapter ones are the "older" versions. The "newer" ones are the USB ones. It says it lasts up to 8 hours fully charged, but it's around 6-7 hours from what I've experienced.
The "old" AC Adapter white headsets have the UPC code "B4E-00004" and the "new" USB Adapter are "B4E-00024", and the Halo3 (USB) is B4E-00038"