Randomyzer

Gotcha.  so it sounds like I should just treat them as separate.  A Mii, game progress etc tied to each console.

The X-Box has never been very good at this either.  I wouldn't know about the new One but I found that progress and similar were a real pain to use or even move across consoles.  The PS3, and now the PS4 was pretty good at it as they did take a network friendly approach.  Still not perfect but I think Sony is the closest.  Apps syncing cleanly (and transparently across iOS and OSX via iCloud has me spoiled.  I'd think the game systems would have that ironed out.

It's more about my kids than myself.  I will likely play on the Wii U almost exclusively.  They will bounce back and forth between the Wii U and the basement, where the other one is.  If it is easy to use the same Mii in both places as well as to retain game progress across the two - great.  If not, they will likely want to start a progress based game in the room where they will want to play it most of the time.  You'd think this would be easy.

does carrying them from one to the other also keep them in sync or are you really just operating independently from each?  Both the Wii and the Wii U will be used.  If they wouldn't stay in sync anyway, is there any advantage to copying it over?