Using an SP4 and it _is_ a good machine
I'm writing this on an SP4 now, and yes I did expense it. Observations from 2 days of use: it's fast, the screen is very nice, the keyboard/trackpad rocks and like the article says, I can sit back in tablet mode when I want to read and mark up a pdf. It can even play games at low res. Furthermore it is half the weight of the laptop and iPad+stylus combo I used to lug around with me before. Battery life is iffy - 5 hours tops on the i7 and more annoying, very slow to charge. There were weird experiences/bugs getting all the patches applied (one update would not install with an SD card in the machine).
If Windows Evernote supported pen input or OneNote could do OCR I would be a happy man.
So the article is pretty spot on, it is good but not perfect but I am not aware of anything else that can meet so many use cases in an acceptable way which is available at this time.