You didn't try the Surface Pro long enough. I have Pro 4 i5 and it's been quite buggy (while it's awesome enough when it works so I don't mind since it seems to work most of the time).

The biggest issue for me is the battery. After filling it with juice it's down to bare minimum in couple of hours.

The second biggest issue for me is the windows update policy - I put the machine to hibernation, and when I come back the windows update has rebooted the machine and shut down my development environment.