It's been around 3 weeks since I have finished installing Mavericks and Win8, and in the last 1-2 weeks I have been struggling hard with wifi drop-outs!
I've tried it all! Re-installed kexts, re-configured all of my wi-fi network (three times!), prayed, and did all kinds of thins you may imagine trying to make wi-fi work properly.
Today I decided I'd format my SSD and install Mavericks from scratch. I noticed that there's a new version of Unibeast out, so I came to download it and then do a clean with the latest versions of Unibeast/Multibeast. I couldn't even download these two little files without my wi-fi dropping out. Most of the times I couldn't remain connected longer than 30 to 60 seconds.
I admit it: I, a grown man, was about to cry!
But then one thing occurred me: I pulled my CPU from under the desk (it seats agains the wall in the corner of my bedroom, and the router sits in the next room), exposing the antennas "in the open". YEAH.... I should have known better. The spot where the CPU was sitting was too cornered under the desk and against the wall. To make it even more ridiculous, the antennas were also too close to the 700 KVA No-Break I use, which I suspect was not helping either.
Moved the CPU to the top of the desk (it's not looking good, but what can I do?) and not only the drop-outs stopped but also my network speed increased considerably! It's been only an hour or so since the problem was solved, so I can't really say for sure it's a definite fix. Nevertheless, i'm feeling quite confident my suffering days are over.
(I'm from Brazil, so, sorry for my english)