I did the upgrade yesterday.
Start up time went from a few seconds to minutes, from what I have read this is common.
I had to update the GeForce video drivers myself on each.
Both had 8.1, I like the view of 10.
So far it feels like every other windows upgrade, it eats up more resources than it's worth. This is a problem if you have an old computer.
The upgrade is free since the machines are so new. I have a 30 day period to revert.