Dell XPS 15(L521x) with Killer 1202 - Potential Wi-Fi Fix
I'd been having some issues with my new Dell XPS 15 in that the wi-fi would drop out every 20 mins or so at home. It has been widely reported that the XPS 15 (L521x) has had wireless problems ranging from poor speeds to limited range with the original Centrino wireless chipsets and apparently the fitting of the Qualcomm Killer 1202 cards was supposed to fix this.
Sadly it appeares not. In conjunction with my Virgin Media Superhub (v.1) it had a very good connection rate using the latest Dell drivers (10.0.1.242), but, as I've said above, the connection would drop out frequently after 20 mins or so and then regularly after that which then had me having to disable\enable the wireless card to regain connectivity. The symptom of this is that the wireless router would be detected, but you get a 'Limited internet connection' type error.
What I have found to rectify the problem (fixed for one week and counting now!) is to use the official Qualcomm drivers (currently on 220.127.116.114) which you can get here: Killer Gaming :: Support :: Driver Downloads
Please note I am using Windows 8 x64, and that you will have to manually uninstall the original wireless drivers and tools before installing.
I know that many here will not be using said laptops, but I hope this helps anyone who comes across it.