Did the update and thus far have experienced no negatives. But I find that the Surface app (edit) - to calibrate the Pen - does not work for me on the S3. It says that the app can't find the device driver. But otherwise, it seems fine.
Yes the W10 updates for the Surface 3 covers a long list of changes.
Surface System Aggregator Firmware update (v1.0.51500.0) improves reliability with the Surface 3 Type Cover
Surface UEFI update (v1.51116.18.0) adds ability within Windows Power & sleep settings to turn off Wi-Fi during sleep. Improved touch support for UEFI menus and support for 3rd party onscreen keyboards improvements.
Microsoft Surface ACPI-Compliant Control Method Batter driver update (v184.108.40.206) ensures correct surface driver is installed.
Wireless Network Controller and Bluetooth driver update (v15.68.9037.59) improves access point compatibility and throughput on 5GHz.
Well that experiment failed. I just had a first ever fatal Display driver crash. Instead of the usual delay then recovery it just went black except for the date time box then froze and never recovered. Had to hold the power button for 30 seconds then power up.
Hmmmm ive never had that, just to clear things up is the display driver crash where the screen goes black and as you said you can only see Time, Date, wifi and Battery, or is it when there's a little flicker and there's a notification (on W10) on the bottom right that the intel display driver crashed and has been rebooted?
I was actually having pen issues.... and then the update finally successfully installed. Problem gone. Battery seems much better. Reliability seems better too. Less crashing, slowdowns, lockups. I've had the update since Monday so... yeah... I'll report back if I notice any issues.