Ok, my experience with my SP4, i7, 256GB SSD, 8GB ram and dock.
Since I got it on Dec 12th and up until this very latest firmware update (this week) every single time i docked with 2x 24" monitors connected, the SP4 would put on a disco display for about 3 mins before settling down. Constantly flashing between all 3 screens (inc SP4 screen). Sometime it would sort itself out, mostly it would leave at least one monitor disconnected, so i had to set them up again.
Coming out of sleep was a nightmare. Sometimes i'd have to reboot.
I raised a ticket with Microshaft, it never got resolved and the buggers even closed the ticket after a few days of 'inactivity' (it was 'testing' as far as i was concerned) so when i replied to the ticket i got nowhere.
I disabled hibernation and set sleep mode so it goes into sleep after hours of inactivity. Locking my screen gave the same disco issues and as i walk around our building regularly it was up to a dozen times a day. So now i leave it unlocked and just hide all open apps to avoid people looking at potentially sensitive data on my screen.
When it does go to sleep and i sucessfully wake it up, all my apps have been closed down.
This has been reported by plenty of other owners too.
MS have been a total bunch of a$$hats in regards to supporting and more importantly COMMUNICATING the issues with the SP4 and the Surface Book.
No wonder they get slated, this time it really is for a good reason.
I actually really like my SP4, but the unfinished state in which it was released is unforgivable imho.