I think powerline technology has recently "matured."
More performance, but at greater cost; isn't that always the tradeoff? :)
Sounds like you have a good situation already, and you can look into any upgrade options as needed at your leisure.
Here is as good as any place to get started on powerline:
http://www.smallnetbuilder.com/lanwan/lanwan-reviews/31624-homeplug-av-500-adapter-roundup.
If there were any way to get Cat5e or better ethernet wire to the seoncd level, that would be the best solution.
We were fortunate enough to pull multiple Cat5 homeruns throughout our home when it was built new in 2000. All of our TIVO's, internet TV's, PS3's, desktops and older laser printers are hung on the gigabit wired backbone, so Netflix, Amazon, and Vudu are all hi def and large file transfers (ie, between the TIVOs) and game play are speedy too. A strong wireless serves phones, ipads, kindles, notebooks and printers. It all works flawlessly (thanks to the Buffalo Router, a 24 port HP gigabit switch, and both wired wireless access points,) which serves up a nice 75/11 Mbps from our ISP everywhere it is needed.
Best/