Sorry to be late to the party, however I thought I would give my experiences as well in regards to this.
I've had my H3 using the TOP RJ45 port since 2015.
After a short period of time with using a non managed 24 port home LAN switch, and since I fiddle around with routers and such which other home users complained about, I changed the Switch configuration around a bit and put my H3 and two Joeys on there own separate switch segment behind the host router. So there connection won't be interrupted by anything I do on the main home switch network. Of course, if I do something at the host router level, then I do this when everyone is in bed or out of the house.
So the Hopper system is connected to a non managed Netgear GS108 coming of the back of the host router. I have another two lines that runs from this 108 switch to the master bedroom were 1 Joey is and then a 2nd line from the 108 switch to the living room down stairs that services the Joey in the living room. There is a Netgear GS 105 switch at these to locations for the Joeys to connect to and other wired devices when needed.
I have had this configuration for over the past few years and haven't seen any problems with it.
Anytime I change out the host router I do power cycle the H3 and Joeys to ensure they get good IP addressing and avoid any IP address collisions.
I've also tested D-Link and HP Procurve branded switches as well.
Other then that, this configuration works and works well.