My first impressions of Windows on the MacBook are:
-Acceptable battery life, equal or not much less than OS X but I'll need more time to evaluate that.
-Good overall UI performance. Possibly better than OS X.
-Poor performance with lots of browser tabs. Worse than on OS X.
-Many strange little annoyances. I shut the lid to go do something else and minutes later and when I open it back up... nothing. Pressing a key does nothing. The whole thing had shut down. Had some difficulty finding the "just right" scaling level. YouTube clarity not as good. There's no way to set the trackpad to allow a light, silent click which is a new feature of the Force Touch trackpad. Another reason I'd prefer OS X. I have it set to tap to click though. Drag click is poor because of a delay.
A more in depth review of my experience to come, after I've had more time with it.
Adding to what SteveJ said:
Browser: Edge is nowhere near ready for prime time, it lacks a ton of features. I use Firefox and the FXC theme, looks identical to Edge if you want that Windows 10 UI appearance but handles tabs, YouTube, favorites, shortcuts, and all the rest like a true modern browser. Better on battery than Chrome if that's how you usually roll.
Battery: I'm assuming you are fluent in Windows and know how to use their highly configurable power management settings, know all the little secrets that eat at battery life, etc. Use Action Center in your tray to toggle the backlight down to 75% or 50% for a nice jump in battery life, I run it at 25% on a dark airplane for extended movie watching. Note that some of the Cortana features can hurt you on battery, like Location (default is 'on') and Voice Commands (I have it turned off) and the dreaded Automatic App Updates (pings the servers).
Lid: In Windows settings, make sure that a lid close equals what you want it to be. Sleep is the quickest to restart but it hurts the battery. Most of us use Hibernate which adds a few seconds to the restart time but saves the battery nicely.
Scaling: I played with this quite a bit, suggest you try setting the resolution to 1920 x 1200 and then adjust the scaling to 150%. I find that this gives me terrific retina resolution and text size that's better on the eyes.
Trackpad: I use a program called TouchFreeze which disables the trackpad when one types there aren't unintended cursor movements. As others have mentioned, there are other programs out there that restore full OSX style gestures like Trackpad+++ but besides the browser 'back' button I am happy with Boot Camp's two finger scroll, etc.
BJ