My experience is the KabyLake SoC is far superior to all previous Core SoC put out by Intel. My concern would be the RAM, the i7 may be a better choice depending on usage.May I ask what issues you have, and how you connected two monitors? Is it the downgrade of CPU power, or less RAM, or both? I also have two monitors, but I don't know what the best options are with a Surface Pro. Is the docking station required to do dual monitors?
[edited to add:]
Just read your reply in the other thread about the monitors.