I usually try different channels on the router to see if that improves performance at all. Experiment with channels on either end instead of the middle.
I wondered if there is any known issues with the wifi hardware in any Samsung TVs?
Recently purchased the UE40H5510 and noticed that in comparison to every other device (phones, tablets, an LG tv even further away from the wireless router), the connection speed is dramatically worse using wifi, streaming internet video or downloading apps.
The router (apple airport express) is right next to the tv, so that couldn't really be improved much further.
Am using ethernet, but would be nice to use wifi if there's anything to try in terms of improving performance there.