Did you ever try out the Cintiq companion?
About this time last year my wife was looking for a laptop like the Surface 3. After reviewing her options she settled on the Lenovo think pad yoga. This uses the Wacon technology for the pen. Its been a year and she is still happy with it. They are not making this any more but you should be able to get one still.
I am now trying out the Surface Pro 4. Its a lot lighter than the Lenovo but so far it looks like its working well. In a few weeks I should be able to make a comparison between these two machines.