Hi,
I bought this laptop around 2 weeks ago and i also have this problem. (This is my first DELL laptop, thought i would give it a try)
I have expensive Cisco router with very stable 400mbit/s download and 40mbit/s upload speed and usually im in range of 4-5 meters. Also i have installed an re-installed my wifi drivers many times and always up to date. Using Win7Pro.
When i play "Counter-Strike: Global Offensive" then in the middle of the game my ping goes up to 200-800 which is really bad, since when ping goes over 100 it starts lagging so much that you cant play anymore. Normaly my ping is 20 or so.
i have tried every solution that has been told on this topic and there is no difference.
So yeah, im really really disappointed to read this topic and the way that DELL is responding on this topic.
Disappointed Customer
m.