Legacy Windows apps that can't address secondary audio devices can have trouble with this device (read the comments).
I originally had the Phonebridge before getting this device on ebay.
I like this since while it comes with goofy front end software, one doesn't need it. All the work is done in hardware.
It consumes the full 500ma that a USB port offers, so it can't be used on a non powered hub. It need you computer, or a powered hub. When in use, it uses only 3% of the USB bandwidth for it's audio.
It works fine on Netmeeting, where you can tell the app what audio device to use. DeltaThree's (ITSP) app also does this too.
To use with legacy apps, one will need to go into the multimedia control panel and change the default audio device to use this.
Any latency I get is not from the device, but from the app.
It also alerts you of incoming voice lines call while in use with a call waiting tone that is made everytime a ring is detected, and by a flashing light on the box itself. That can get annoying if a telemarketer is calling (10 rings=10 tones). Switching from voice line to internet mode is done by hitting the # key twice on the connected phone. Switching back is the same way. Too bad the Phonebridge can't do that.
Also, since this is like a sound card to Windows, one won't have to adjust volume controls every time they want to make an internet call, since it does not use your sound card.
When I installed it (on XP), the USB audio was detected w/o issues, using Microsoft drivers, there is another device that provides communication for the included software, but I have disabled that in my device manager. It is not needed for basic usage.
I do not have the included frontend software installed, just the disabled device.
It would be nice if Actiontec made a little app that would switch the default audio device on a double click, but it isn't like I can't switch w/o it.
All in all, I love it, and it has helped me to keep the LD bills from 25 bucks, to 2 a month.
It has already paid off for itself in a month, considering on ebay, I got it used for 20 bucks with shipping.