I spoke too soon. The Minix Neo X7 is not as mature as other NMTs. I think the Archos video player is also lacking.
First of all, the X7 can only produce progressive scan outputs (i.e. 480p, 720p, 1080p). This means that if your system is a 1080i system then the X7 will convert it down to 720p even if your file is 1080p to begin with. Our projector is still 1080i, even though the rest of the system is 1080p, so I've been looking at 720p ... upgrade?! ... but still good enough. I suspect this is a limitation of the hardware so it may not be fixed with a firmware upgrade.
Sound for me is actually more important that the screen resolution so the next problem was the "deal breaker". It seems that the X7 cannot output 5.1 or higher, at least through the HDMI port, I did not try the optical port. Its sound subsystem does have several options including a "passthrough" option which passes the decoding job to the next device which in our case is a Yamaha RX-V3800, but according the 3800 only a stereo signal was getting to it. I though it might be my Archos application however after trying VLC and the native player with no luck, I have to guess it is a problem with the firmware or the hardware.
Am downloading a custom firmware now and will try again.
This is disappointing because the quad core performance is very refreshing compared to that of our Mede8er 500X2 (I think), but ...