Have a Surface pro 3, which I like. It wasn't very useful with Win 8, but Win 10 changed its usability overnight. I was considering upgrading to the SP4, but I couldn't really find enough improvements ti justify the expense, so I did the next best thing and ordered the new keyboard. In my opinion, that was a night and day improvement. I will likely buy an SP5, next year.
But I did a heck of a lot of soul-searching, as I'm in the middle of a Mac refresh. Ultimately, it was the family's reliance upon the Apple ecosystem that kept me on Macs. So, the woman and I got some open-box MacBooks (saved a bundle) and I got a ew 5k iMac. Pretty exciting, as we normally stagger upgrades, but the woman's MBA died at the same time I was slated to update my iMac.
Anyhow, I did a lot of testing and soul-searching. The woman even played with a Surface 3 (not the pro) for a couple weeks. We both agreed that it was close, but we're too tied up in iTunes/iPhoto/ATVs/iPhones/etc. for new.
If Apple doesn't have a hybrid device in 2-3 years, we'll probably wind up migrating.