If you have any decent quality stuff you are streaming I would upgrade to an N router.
I just did a $20 TPLink router and the speed of my Plex streaming increased along with the quality of the media through my ChromeCast.
We'll see how the Fire Stick works with it. (not scheduled till next month. blah) Only bought it so I can have a remote. The plex app works fine on my Android but sometimes you just want a remote.
On a side note.
If any of you guys aren't set on LED 60's, Samsung has a 60" Plasma for $699 (starting next week)
Probably a better quality tv than the cheap LED's. imo.