It's pretty cool for the people who like to decorate and play around in the game. Although you can't even go in the beds and things like that, it's pretty cool to have. In my opinion, I think it wastes my time and my money.
And with the items that play music, I think you should be able to activate them and have whatever song they play become the background music to the Villa until you either use another music item, save the game and turn it off, or exit the Villa. Instead, you can only listen when you press "A" and the song plays until you stop "talking" to the item. (Now, I've only done this with the Music Box. If the piano does what I said before, then awesome.)
The only problem. But I still like it.@ pink- yes, all important NPCs visit it, excepting the Galactics and perhaps your rival.
You should be able to throw parties and battle the trainers/people that come.. and use a phone to call all of the people that you met or battled so you can invite them or talk to them