I had been using Windows Technical Preview since it was released to the insiders on my Surface Pro 3, which infact I use for my day to day work. I was having some trouble and some applications which are really important for me was having problems.
Please follow this post for reverting back to Windows 8.1 from Windows 10 Technical preview. I had some trouble downloading the recovery USB Image, the file size is about 6.3 GB for surface pro 3, but the rollback from Windows 10 to 8.1 went smoothly. I was bit worried about the license key as I had forgot to keep a record, but I could get the serial number of my Surface Pro 3 from the back side of the device which is more than enough to prepare and download the recovery USB Image.
I am still using my Surface Pro 2 with Windows Technical Preview to have the updates.
Anybody in the same boat who is reluctant for the roll back – Please follow that post, it would take just about an hour for the entire process