I experience the same issue when my phone is connected to my Surface Pro 128 via Bluetooth. I'm a basic user, but could we be experiencing some type of Bluetooth bandwidth issue? If so, will driver updates fix the issue? I would like to be able to have more than one Bluetooth device connected to my Surface Pro at one time.
Here are some more observations regarding the mouse pointer lag issue:
- when there is no WiFi HotSpot around then I'm using Blutooth Tethering via my Samsung Galaxy Note. In such a configuration I don't have a lag with the BT Wedge Touch Mouse (as long as the BT keyboard isn't connected too). I wouldn't expect a BT bandwidth limitation when using a BT keyboard since some key strokes won't cause heavy traffic.
- I recently tested with another BT Mouse (Logitech M555b http://www.logitech.com/en-us/support/5747?section=overview&crid=398&osid=23&bit=64) and - surprise - there was no lag in mouse pointer movement with this Logitech Mouse when the BT keyboard was connected too!
So it seems that - in my case - there is "only" a BT issue when using the BT keyboard in conjunction with the Microsoft Wedge Touch Mouse on a Microsoft Surface Pro!?!
For now I'm going to use the Logitech Mouse instead of the MS Mouse when I'm at home/office doing intensive text processing (Word, VS etc.) with the BT keyboard. The Wedge Touse Mouse is currently only good for me when travelling without the large BT keyboard.