Choppy video playback with airplay from Macbook Pro

I experience very choppy video using airplay towards my Airplay unit (3rd gen).

I am using a Macbook Pro (15" retina, late 2013 version) with these specifications:

- Intel Core i7 2.7 GHz.

- 16 GB ram.

- 768 GB flash/SSD.

...and so on. I have the Mavericks OS installed (10.9.1).

When I duplicate or extend the screen of the computer to my Apple TV it is chopping EXTREMELY much. I am not talking a little bit - but it is not even watchable. I thought that it could be the router itself as the connection is (probably, correct me if I am wrong anyone) is directed from the computer - to the router - and then to the Apple TV, which could make the router like a filter in the process. And if something would prevent the signal from reaching the Apple TV with "full speed" it could prevent the actuall image.

However, when I am using the iPhone 4S and streaming video (both video found in my phone as well as streamed TV from apps such as Magine.com) the image flows completely flawless. There are not even a touch of lagging. It flows perfect, just as watching a movie directly on the TV.

The networking hardware in the phone is slower than in the Macbook Pro retina (late 2013) - both for sending and recieving data. But still... my iPhone works better than the Macbook Pro for the Apple TV. Even though that the processing, memory, graphic and networking power is probably a thousand times faster in the computer... it still performs really bad.

I have followed some discussion threads here (https://discussions.apple.com/thread/4342095?answerId=22051725022#22051725022 and https://discussions.apple.com/thread/5734226?tstart=0 just as a couple of examples). I have accessed my router (Netgear Gigabit EVG 2000) and increased the Wireless mode to "up to 270 Mbps. I have also followed the previously linked threads and disabled the WMM (in the QoS-section). I felt that this made a little bit of a difference...

...when I am mirroring the screen and scale down the resolution to match the AirPlay screen (full-HD, 1920 x 1080) it works okay, but still chops quite a bit almost all the time. But if I extend the screen and want to watch TV at the same time as I am doing something else on the computer - then it chops so that it is not even possible to watch.

This have to be something either with the Mavericks OS or with my network settings - can anyone help me...? It would mean A LOT!