[Android Head-Units] Blaze Falconburger:
I eventually received my unit and have had it in now for a few weeks - coming from an MTCB it is much better - audio quality is actually pretty decent, way better than the MTCB (I only have uprated speakers, no external amp or sub), and the speed of the unit to boot and in operation is lightning fast in comparison.

I'm using PowerAmp and the Folder view with a USB disk with around 300GB of MP3s on, which only required the single USB connection to power it, not an additional one. It catalogs it way quicker than the MTCB used to - I don't use the library view, that just doesn't work for me. I mounted the hard disk in the glove box on some velcro and ran the cable through to the head unit, very easy.

I mostly use Waze for navigation, or Google Maps or the installed iGO - all work well, though I haven't used them in too much depth

Bluetooth - works for phone calls, I've not tried audio or OBD adapters over it

FM - I plugged it in as reception is bad here so I can't listen to anything when moving as it keeps cutting in and out, but I haven't even tested it works - I do remember seeing the 2 connectors on the back of the head unit, I didn't realise they were different. I'll try later and see what I've broken :D

Steering wheel controls worked out the box perfectly

I am considering adding a DAB adapter to give some kind of radio ability

Niggles

I'm not sure if the radio always properly hibernates. I think the value in the menu is set to 10 minutes, but plenty of times I have come back after it has been parked for 12 hours and it has done the quick resume. I've also had a random flat battery since fitting this head unit after the car was parked again for about 12 hours - totally dead, it wouldn't even crank. I never had this before, and I didn't find anything else on which would have caused it to totally drain. I haven't had it since, but it's only been in for 3-4 weeks.

Also a few times it has totally reset the settings - it's obvious when it powers on as the time is always wrong - it's nearly always 16 hours behind, the keypad touch tones are back on and the EQ has reset. I'm not sure what causes this, but at least the car has always started when this is the case.

Reversing - I don't have a reverse camera but everytime I reverse the head unit keeps switching to show a black screen with reverse lines - I couldn't see a way to fully disable this in the menu, so I probably need to remove a reverse signal wire (assuming it's not done over the can bus)

Fitting - in the UK E46 the air vent ducting behind the head unit is not parallel to the head unit - it is closer to the passenger side (left hand side as facing the head unit), leaving more room behind the right hand side. So where are the connectors? All on the left hand side, meaning everything is tight and bent at awkward angles as it comes out of the head unit.

Also - the amount of boxes and cables - I'm not sure if it's more or if everything is just bigger than the MTCB I had (which also had separate can bus box), but it was a very tight fit and took ages to route things as best I could to all the head unit to eventually seat all the way in. Fiddly, but possible