These comments, and others in other threads, simply reinforce the "different strokes for different folks" observation.
I have the SP3 and really like it - I don't like it's very limited graphics capability. I like it's portability, but I use it mostly in the MS dock on my desk hooked up to all sorts of stuff including a large monitor. I don't have to do multiple meetings, or business trips, as many of you do, so I only carry it out of my house (office is in my house) maybe once a week, and it's with me on any trip I might make. Even when I use it in "tablet" mode (my tablet mode, not MS's idea of tablet mode), I keep the type cover attached in every instance using, mostly, the desktop. Yes, it's attached when I'm sitting on the couch with it in my lap using touch on the screen. I detest on-screen keyboards, but the type cover helps in stability on the lap plus I can quickly type away on something if needed.
Enter the Surface Book. When I first saw the SB, it struck a real cord. You see, I'm one of those guys that really likes the SP, but really my orientation is more from the other end of the telescope: I'm much more in favor of the SB where I can remove the clipboard when needed, which would probably be only 10% of the time. That's my use case, so SB here I come! Just have to figure out which major home appliance to I want to sell to finance it...