Now I'm wondering if there're two separate issues - the disconnection/instability issue, and the BT interference issue. I haven't encountered the former - my connections so far have been stable, although I have the i5 version and the above poster mentioned that the i5 versions don't seem to have this issue anymore. The BT interference issue still annoys me since it's been there since the SP1. I encounter it on a daily basis because I connect a BT keyboard, mouse, and headphone to my SP3 and the mouse is completely unusable when there's a file transfer over WiFi going on due to the interference! Ugh.
The specific issue that this thread was started on was the 72Mbps cap on wifi connection speeds. That issue still exist unless you take steps to work around it. I personally believe that the cap is done intentionally by Microsoft to deal with issues like BT interference and power savings. Now that customers are voicing their concerns regarding this limitation they're probably going to either remove it completely or give end users some type of toggle with a warning stating that disabling the feature will reduce battery life and BT performance. (Just my opinion).