Thought I'd give this a try after this months updates, but if you did, you'd still notice that streaming audio of BT and trying to stream a movie or rather just use the internet would kill your download speed. I did a little bit of searching, and some people with SP didn't have this issue prior to Windows 8.1. I decided to try to find stock SP1 drivers for BT and Wifi and I believe I did. I installed them, and now I'm currently streaming a 1080p video on Crunchyroll while using my Motorola Buds (BT headset). Previously I could not even stream at SD. Running tests on Speakeast Speedtest would get me speeds of 0.33 Mbps. The drivers I found are here. I found that through this. I know get my 15 Mbps connection running Speakeasy's test while streaming music. One thing to advise, is hide the latest hardware update using Control Panel so the drivers don't update. YMMV
EDIT: My router only supports 2.4 GHz
EDIT: My router only supports 2.4 GHz