Any desktop should be at least somewhat hardware accelerated, as the X driver maps EXA stuff like composites to the GC320.
(I should clarify this doesn't extend to stuff that only supports full OpenGL, but all 'traditional' desktops should benefit from this.)
It appears as a conventional serial device producing NMEA strings, like any other GPS, but you need to send some AT commands to the modem for this to work first and I'm not sure there is a nice script for this yet.
I think one of the differences is that rather more people actually care about the Intel kernel and Xorg drivers, whereas we are the only people left who care about OMAP5.
Particularly for Windows (and also Linux now I suspect too), these drivers will actually be being actively developed and...
imo, it's the GPU that's the weak point not the CPU. Lack of OpenGL ES3, Vulkan, or any realistic chance of open drivers are quite limiting, whereas the Cortex A15 still has plenty of raw power. Lack of ARM64 is a shame, but with a few exceptions it's easier to recompile software than make it...
However much I would like a camera; it is worth bearing in mind that there is little documented evidence of the OMAP5 camera interface ever actually working (certainly not since TI's ancient 3.x kernel), so it likely would have presented quite a bit more software pain.
Here are some instructions to try (I haven't actually tried them verbatim yet so expect problems...).
If you aren't on Buster already, you can start from this image: https://packages.pyra-handheld.com/rootfs/buster/mate.img.7z
sudo apt-get update
sudo apt-get install...
The extra pin is a thermistor. 10k is most typical, but I don't know what the Pandora actually uses so it might be worth measuring (they are usually specced as resistance at 25 degrees but room temperature is close enough). A thermistor of a suitable value next to the lipo should be accurate...
At least in the UK, 5G will eventually be deployed in the 700MHz band (somewhat controversially as this will result in the scrapping of 700MHz audio equipment) so would give similar range to 4G. But given that 4G has been around a long time and 3G switch off is only just being talked about, I...
I read that as a pico projector integrated into the Pyra, for which space is a little tight!
I don't think there's much accessible IO, maybe a few pads you could just about solder too, being mindful that the OMAP5 mostly uses 1.8V IO.
In terms of external display, there is an HDMI-out port but the software for that isn't quite finished yet (the automatic resolution negotation code in the kernel is getting confused by the rotation.)
As for the other suggestions, I hope they aren't serious.
I will get things written up over the next couple of days, the 3D and X11 stuff is definitely at a state where it is testing-worthy now (main remaining issues are the tearing at the left of the screen, and external display support.)
In terms of the audio, that is a quick test to do on whatever...