HDMI-out,
For a usual 8.5-inch tablet is that I mainly use the 8.5-inch screen at outdoors, but indoor or a hotel room the tablet will be used as my main computer tool when, well then I would more be willing to connect it to a larger display device (monitor or HDTV), not just a small screen.
I have a set of HDMI kit, also able to connect to DVI or VGA, not just the HDMI of display is available, like this
My HDMI Travel Kit (for a Toshiba WT8-A 8-inch tablet), posted at 09-26-2014 06:50 AM:
http://forums.toshiba.com/t5/Encore-Tablets/%C2%B5HDMI-to-VGA-converter-that-works-with-Encore-8/m-p/616201#M8354
a "one size fits all" connector,
Never want to get an only USB port to be acted as a video port part-time, unless it comes with the two USB ports at least, but is still with another HDMI-out port would be better.
did you know about the newest Macbook has attracted Apple fans' anger? ----- "And like the iPad, it only has one port, which is the cause of the outcry."
http://techcrunch.com/2015/03/10/apples-latest-betrayal/
e-Compass,
When you came into a cavern or tunnel, GPS becomes unavailable, have to use the e-Compass.
Besides that, the e-Compass is also more uses, for example, when came into a strange place you can be beforehand to know about local Sunrise position via using the e-Compass, very useful to a shooter.