I just updated my access point because of what happened afterwards I now for sure the problem is driver related to the N7260 and it has to do with something interfering between bluetooth and wifi.
The problem is worse depending on the driver version, and the latest drivers are worse then older onces
My new access point is an engenius ECB600 - 2.4 and 5 Ghz
After installing I suddenly had much beter fast up to 300Mbps without dropping the wifi connection, the drivers for bluetooth where the latest available on the intel website, the drivers for wifi where the 16.6.08 wifi drivers (not the latest)
I decided to be safe to updgrade to the latest wifi drivers on the intel website, that was a mistake ever since doing that I had very bad connection, lots of complete dropouts + my wireless bluetooth mouse froze a couple of times for a couple of minutes.
After that I decided to go back to the Sony VAIO MUltiflip certified drivers which are 16.6.08 wifi drivers and 3.1.1307.0362 bluetooth drivers. Inel connection settings are turned off. Result higher connection rates for wifi all seems a lot better, but I am still wary because problems have been around ever since i bought my ssony multiflip .
We will see the coming days.
INTEL and MICROSOFT should have solved this long ago, it all strated after updating from windows 8 to 8.1.