To be honest with you XU4 was also my first option but the integrated GPS on the DB410c made me choose it as the "better" alternative.
Currently i invested another few bucks in a external passive gps antenna because the integrated one seems to have problems.
GPS passive antena link (ebay)
For the moment i just loaded a custom launcher on in for in car navigation system.
Last night i have received the touchscreen, which i didn't have time to test if its compatible with this board, still waiting for the 7" LCD (1024x600) for it.
I really hope that it will work out of the box because i don't want to stay and inject the drivers into Android.
I intend to add a small fan to the board powered by GPIO but i need to test if the fan stops when the board goes to sleep.
In idlle the CPU is at 60 - 65 celsius degree and from my point of view its to much if you take into consideration that in the summer you can have easyly over 40 degree ambient temperature.
I will document all the progress on my youtube channel Home Made Navigation System
Currently i'm designing a bracket to add on the back of the LCD that will hold the DB410C + touchscreen controler + lcd controler + fan.
On the board i need to make some modification like adding a "second S2 button" conected to the GPIO and also to add audio jack.
More things will follow.