So after doing the registry fix, everything was good until yesterday. Then suddenly I started to get disconnects and it got so bad it was minutes apart. I have now set my router to a/n mixed from a/n/ac mixed. Since then, things seem stable again.
If you are still having issues, you may want to try this utility: WLAN Optimizer - Optimize wireless gaming, audio and video streaming...
Just disable autoconfig and restart.
You can try downloading Newtwork Speed Test app from the Store to test your speeds before and after.
It improved my speeds 40-50%. There seems to be some issue that your Surface will continuously refresh and refresh wireless networks wasting cycles.