The wattage is less on the Surface Pro 4 and Book. However the Surface Pro and Book had an update or will be having an update that enables Speed Shift on Skylake CPU's.
From what I have been reading, the pen on the Sony has a much slower reaction time than the Surface. Also, keep this in mind. The Surface is to a Nexus as The Vaio is to a Samsung Galaxy Sx. The reason, Sony loads bloat like none other which could be the biggest issue with lag on the tablet.