Yes if you are in the market to buy a new tv then I would recommend one.
I have a 2015 4k Sony and love it.
It does a very good job with upscaling, especially 1080p Blue ray content
480p doesn't look too crash hot on it though.
Saying that, I dont watch alot of TV, just Netflix, movies and youtube or anything off my HTPC..
4k youtube and netflix (some titles) look fantastic
On the Google play store there is now a 4k video app, although the titles are not cheap! and im not sure if they are true 4k.