My SP3 with W10 pre installed has the new Windows logo etched into the space under the kickstand and also has the device storage size below that. No windows 8.1 pro, although I have had 1 defective SP3 with W10 pre installed that came with the old Windows 8.1 pro logo. I chalked that up to a change mid manufacturing cycle. Additionally on all W10 shipped SP3's the sticker on the power supply says Windows Pro. And of course they have deep registration with Microsoft so you don't need your product key when doing a full disk wipe and reinstall with the factory image. In fact unlike units with Win8.1, the ones with w10 installed from factory won't even ask you for the product key when doing a fresh install from the generic ISO.