I had the same issue with this device. I ended up writing some code that you could run on a machine to operate the switching via the RS232 port: https://github.com/timgws/kvm-switch/
Bonus for adding 'glide and switch' functionality, so you can move the mouse to the edge of the screen and it would jump the input to the next display in your layout. It's like a hardware version of Synergy.
Very finicky device, but if you don't touch it - and you don't use any of the shortcuts - it works.
Neat! I used to use ShareMouse (pay-ware, if you want more than two machines tied together) for this, because setting it up and keeping it working are so easy compared to whatever version of Synergy existed at the time.
Synergy made me manually configure my monitors by dragging little boxes around in a window, would frequently refuse to connect, would spontaneously disconnect, and repeatedly mangled my config such that I had to keep manually configuring it over again.
With ShareMouse, it was "open a copy of it on each machine, slide mouse in direction of next machine, then optionally enable encryption (to prevent other users' instances of ShareMouse from being able to attach)".
This one has been around a bit longer, too, and despite its name is now much more than just a pretty face for GDB but rather a full cross-platform development environment which has IntelliSense everywhere, handles the installation of toolchains and BSPs for embedded targets, building kernel modules (with VisualKernel addon), etc.
I'm not currently building a WISP, I'm building an auxiliary business for WISPs (Email in my profile if you're curious what it is - not really trying to promote here just yet) but since you asked I'll answer from past experience:
1) I've used Cambium and Ubiquiti and several others. Ubiquiti is hard to avoid because it's so damn cheap and it does work reasonably well, although Cambium is noticeably more robust. The latest stuff coming out is fixed 4G LTE, several companies pushing that gear in to the WISP space and I suspect that's where things will start to take off.
2) 30-50 for Cambium and Ubiquiti APs. Fewer if possible. On a large network the APs tend to be the bottle neck.
3) Fiber to primary POPs and then high capacity licensed wireless backhauls 2 to maybe 3 towers deep in the network. Depending on the local weather it's not unrealistic to get a licensed link that can support 800mbps to maybe 1.2 gbps over 3 to maybe 5 miles.
I have been using the BlackBerry Priv since it's release. One of the best things they have going for them is how quickly they apply the android security patches once they are available.
I think they have released every security patch on the day of the public disclosure since the Priv released. This blog post shows the release dates up until March atleast, and they've hit the Nexus release dates on all of them.
Samsung follows the carriers where as I think they have the power that apple has to force carriers to do their bidding. My S6 edge is a few months behind android patch level but I know for a fact that the exact same model in other countries is on patch 1st July patch level. Its the same damn phone.
Some people complain that old models are obsolete but what about the same newish model getting the latest security patch in one country and not in another.
Another commenter posted that the L1Techs KVM are Rextron devices. The Startech switches are rebranded ConnectPro KVMs.