For what it is worth...A 4x4 Matrix HDMI switch is just that. A Digital Switch that allows for multi display posts from any of the 4 inputs. All HDMI...All Digital in and out. It will give you the best image it can based on the display that is using it. HDMI is the current standard for connection of digital content.
Coxal can be used also for HD, but requires it to either come out of the air or use a RF modulator to make the video into an RF channel and send that over the cable and then you turn the freq you need. Still not as nice as HDMI.
All in all, if you do not have an HDMI switcher now, you will have wire the coach with HDMI and that will prove to be a lot of fun. I am shocked and amazed to read your 2013 coach does not have a 4X4 switch.
I converted my 2008 Tour Master to all HDMI with a 4X4 switch years back. Showed it to some RV manufacturers at shows and rallies about what the future holds and what they should be doing. I was happy to not only see the new coaches doing it, but also using the same HDMI switch that I had shown.
It should have started back in 2009 but they would not pay the cost of the switches and the HDMI cables. (It took a 75 foot HDMI cable to go from the front of out coach to the bed room based on the path it needed to take. Ouch!)
All in all, you might be better off looking into Wireless HDMI solutions if you want HiDef and not needing to run the cables.
I was happy that the our new TOUR 42GD on order is properly wired with the same 4x4 Matrix Switch I speced out a few years back.
BTW...Here is the one I believe is being OEM'ed by Winniebago...
Amazon.com: Monoprice 4x4 Matrix HDMI Switch & Splitter with Remote: Electronics
Also note that if you go over 25 feet, you will need a booster unless you go over cat5 cable. (Boosters are cheep though.)
Seeing I have not looked closely at the black of the unit, they may be using the model right before this one.