[MTCD Android Head Units General] SkyBeam2048:
I can add some information to KLD:

Actually I just sucessfully flashed my MTCD KLD 2.41 MCU with MTCD HA 2.61 MCU firmware.

Upgrading and settings

Some notes:

After the upgrade it lost some settings:

DVD setting: On the first page of the factory settings DVD was enabled. Thus the device shows the "eject" button in the status bar. Even though I am not running HA ROM and I don't have a DVD drive at all. Disabling DVD makes the icon disappear.

Radio Setting: I had to chose the correct radio region again.

Soft touch buttons: My buttons initially worked except the power button, I went into factory settings to remap them all which worked perfectly.

Hardware buttons: My hardware reset button (the only hardware button on my device) did not have any function after the upgrade. Remapped it too in factory settings button assignment.

Button LED setting: My buttons were enlighted with light blue color after the upgrade. In factory settings "other" I switched it to "RGB LED". After this change I could simply control the LED color and brightness again in android settings.

Everything else was kept as far as I remember. But it might well be that the defaults just match my device and everything got reset actually.

My MD725 Bluetooth module was still configured properly (though perhaps just because it's the first option in the selection box).

In Android settings I found the "beep" volume reset to "high" which was very annoying and terribly loud. Swiched it to "low" again, problem solved.

Bluetooth pairing:

I got some issues first with Bluetooth pairing. In Android settings i could not connect to any device despite I could set device name and PIN. Then I discovered the Bluetooth app is able to pair my phone and OBD adapter perfectly. It's also able to connect/disconnect them properly. No clue yet why Android settings does not work. But I don't care too much.

More settings:

I also noticed that in factory settings I have more options now to bind actions to hardware buttons. For example I can't remember having the option to blank the screen on button press. I still don't have this option in the steering wheel control app on my unit but this is a ROM issue.

In addition I found a switch in the factory settings "other" screen at the bottom which allows to attenuate the amplifier. Now running mine at -3dB/-6dB (still trying) which allows me to run the amplifier at a bit lower volume. Previously the lowest volume (setting "1") was a bit loud for me especially when used while the car is parked. My subjective feeling is also the noise level without any running audio source decreased. But I might be wrong on that as I did not measure this to have clear figures.

Other findings:

So far it looks for me like MTCD HA MCU is fully compatible with my MTCD device (it's a 9 inch 1024x600 unit for Subaru much like this here).

I also noticed that since the upgrade it seems to be possible to use Bluetooth and WiFi at full speed in parallel. Not sure though if it's due to the MCU as I did some heavy antenna setup modifications recently as well:

WLAN antenna: I put some +8dBI antennas right under the center dash at the windshield. It's not as good as an external antenna but sooo much better than the cheap cable (it was not a real antenna) my unit had. I used 2 antennas which are 2.4/5GHz compatible even though my unit currently does not have 5GHz WLAN.

Cabling: Used RG405 cables to connect the solder points of my MD725 chip to the back SMA connectors and from there to the antennas in the dash.

Rooftop antenna: Mounted an ABB (Antennentechnick Bad Blankenburg 3785.01 rooftop antenna with +20dB gain on DAB+ and GPS for great reception. Though not related to WLAN as there is unfortunately no rooftop antenna available with FM/DAB/GPS + WiFi.