I switched from Surface Pro 4 to Surface Book 2 a couple of months ago. My main gripe with the SP4 was *battery life*. I'm sure the SP 2017 is better than the SP4, but I wanted as much as possible... I actually liked the size of the SP4 better than that of the SB2, and the keyboard of the SP4 was ok (although that of the SB2 is better).
What would I wish to go for a Surface Pro next time?
* Same width/length as the SP4.
* Thinner bezel = larger screen -- say 13" instead of 12.3".
* Slightly thicker and heavier is ok -- give me similar battery life as that of the SB2.
* For my use, I don't need a fancy graphics processor, but of course, I don't mind an improvement from that of SP4.
* Fast internal SSD (like on the 1TB SB2, or faster).
* Probably Thunderbolt.
* I'd prefer SD card reader (for camera cards).
* LTE or 5G would be nice -- provided that it is possible to get unlimited data plans which don't cost an arm and a leg.
--
I'm a little puzzled by the performance of the SB2. I have run a MATLAB benchmark test on the SB2, and it is barely faster than the Surface Pro 3. Maybe because it ran on battery (throttling), maybe because the clock frequency is slower, maybe because the benchmark didn't utilize multiple cores (did it? don't know...).