[8525, TyTN, MDA Vario II, JasJam Accessories] Arktronic:
I just bought an MEX-BT2500 and had it installed - all at Circuit City, for the Americans on this forum.

Since I literally *just* got it, I will give an initial impression and then update this in a few days probably with some more info.

INITIAL IMPRESSION

Well, it looks nice. The buttons have blue LEDs. But that's not very important. Pairing it with the Hermes was pretty painless, you just turn it off and then hold the Equalizer/Bluetooth button >7 seconds. The passcode is, of course, 0000. It has three separate Bluetooth icons - one for it being off/on/discoverable, one for hands-free being connected, and one for A2DP being connected.

When re-pairing after turning it off or something, the A2DP mode does not reconnect automatically. I've tried pressing 6 (Pause) and that made it reconnect. Maybe there are other ways of doing it, I don't know.

I am still experimenting with the A2DP settings to figure out what sounds best - I am using the Microsoft stack, so I'm not expecting miracles here - so far, it sounds OK at BitPool/MaxBitPool = 58 and Joint Stereo = 1. Contrary to popular belief, Joint Stereo is NOT mono, but I have yet to determine whether the Microsoft stack thinks that. I just need to play the right song. I read somewhere on this forum that increasing BitPool/MaxBitPool to 72 while keeping Joint Stereo on sounds good, so I'll try that later.

I will try the hands-free mode later on as well. Updates to follow.

UPDATE 1: More on A2DP (and a bit of hands-free)

I set both of the BitPool values to 72 and enabled Joint Stereo. It works well. The sound is most definitely stereo, and the quality is a lot better than what it was with a lower BitPool and Joint Stereo off. I've never tried the Widcomm stack, so I can't compare it to that. I also tried hands-free calling, but it did not work at all. That turned out to be an issue with the ROM (because it no longer worked with my HT820 either), which has since been resolved by flashing a different ROM. One extremely disappointing thing is that it looks like, for making calls, you can only initiate a redial from the device. I haven't looked into that too much yet.

UPDATE 2: Hands-free

I still haven't been able to make it do anything but redial for initiating calls, but the call quality appears to be quite good, both for the person on the other end and for me. I have to say, I'm impressed by that, especially since the Parrot MK6000 apparently has a huge separate dual microphone that you have to mount in order to get clarity.

One thing that has started to annoy me is the beeping when I turn off my car. Apparently it's to remind me to take off the faceplate, but I don't always want to do that and it pretty damn annoying. I don't believe there is a way to turn that off. You can turn off other beeps, but not that one.

UPDATE 3: A2DP again

The wireless stereo really does work well! The Hermes is able to handle receiving Internet radio streams (www.di.fm in my case) and piping them through A2DP just fine using MortPlayer. Speaking of which, AVRCP works well. Play/pause, previous, and next buttons all work, but with a slight (<1 sec) delay, which is caused by something other than the BT2500 because the same delay occurs with the Motorola HT820. It's either an issue with MortPlayer or the Microsoft stack - I don't know which one since that is the only combination I've used that supports AVRCP.

One thing I have yet to try is receiving a call while listening to music. I will try to do it tomorrow and see what happens.