Model railroads.

I have the Prodigy (Advance but not squared) and it has worked very well for me despite the shots other DCC system users like to take. I've had it for over a decade.

I bought a used on off ebay for $100, then I bought two additional throttles for around $20 each, and finally a complete second system as a backup (with a 4th throttle) for $50 because the listing wasn't in the right category an no one else bid.

it does have some quirks, and the one I can think of off the top of my head is that it doesn't necessarily remember the locos you have recently used unless you unplug the throttle from the cable . It will display "SVD A" and then the addresses you currently have on the recall stack will be saved when it is powered off.

BTW, you can use "regular" Cat5 ethernet cable and connectors to extend the connections, and even an rj45 splitter. I have a splitter connection (can accept two throttles) or two on each wall. No need to buy the MRC brand extensions at 3-5 times the price of generic Cat5.

I haven't added the wireless because I don't mind a 15' cable that I can relocate to each wall.