Not a book but I have a Pro 4 and prior to that a Pro 3. I love the portability of it but I've run into a fair number of issues. My windows Hello is intermittent, phantom restarts, not sleeping properly, dead pixels, light leaking from the bezel. My wife's Pro 4 wouldn't connect to wifi hotspots properly and despite multiple visits to the Microsoft store, they just chalked it up to "This stuff happens." The kickstand is great for media consumption (something they should have put into the Book) but on the lap not so much. If they Surface Book were to get a kickstand I would consider getting it. I'm about 18 months into this Pro 4 and I'm waiting for a replacement unit to come in so I can swap it out due to the dead pixels.
All in all, it's definitely not as sturdy as a Mac nor is Microsoft as compliant in dealing with my issues as Apple. My previous laptop was a 2011 Macbook Pro and I used that for 4 years with no issue. I sold it and it was still in great working condition. Apple swapped out for a current model year when I brought it in for a speaker issue with no questions asked (this was when I bought a 2010 refurb).
On that note, there's supposed to be a new Surface announcement at the Future Decoded event at the end of October. No news on what that is yet.
http://bgr.com/2017/09/06/windows-10...-release-date/