It's been interesting reading through more than 2 years of posts in this thread. I have to say I was not aware of wifi issues on my laptop until just recently, and apparently for a very good reason.
I have an Asus Zenbook UX31A. It came with Windows 8. My intention was to reinstall it with Ubuntu when I first got it and so that's what I did. All drivers and hardware were pretty stable there. No wifi issues.
I recently decided to reinstall to Windows 7 due to some needs that required it. I started noticing my wifi would drop out. Sometimes it would reconnect after a few seconds then return. Other times it would never return and I'd have to force it to reconnect. I had several of these occur while reading through this thread. This problem appears regardless which wifi band I'm using (2.4GHz or 5GHz). My routers (yes, multiple) are set to fixed channels.
All of my laptop's drivers are up to date as far as I can tell. When I redownloaded the latest wifi drivers from intel.com and went to install, it asked to repair, which generally indicates it was already installed. Still no solution to the problem.
I have a Centrino 6230 just laying around, but I've seen a few comments here the problem persists so I'm hesitant to try it.
Understanding there may be some regulatory problems installing my own adapter, it really feels like the only course of action that fully resolves this issue in Windows is to purchase a non-Intel adapter.
I am not willing to be one of Intel's driver guinea pigs. One of my biggest complaints about Linux based operating systems is there are many places where you have to tweak things to make it work. I had my Ubuntu install stable and working. I want this to JUST WORK. If it doesn't JUST WORK, and I have to play around with it to get it to do what it was advertised to do, then, in my opinion, it's broken and needs replacement.
I've seen a few recommendations for adapters that appear to work fine. I will likely go down that road to fix this. I don't need widi, though it would have been a nice to have feature. There's other ways to achieve this, anyway.
I am tech savvy. I have been working in technical support, administration, engineering, and architecture over the past decade or so. I've built my own systems and have already gotten past the phase of trying various tweaks and changes to make things do things. This is a system where my preference is for things to do what they're suppose to do, as advertised, so that I don't have to spend hours upon hours making it work.