I use C2 regularly on my Surface Pro 3. It is far from the best in terms of usability, but it does get a lot of use simply due to how portable it is, while still running Windows. I do use a Bluetooth mouse, as I can't stand trackpads and I was unable to get away with touchscreen/pen only (the pen is definitely nice for making quick placeholder doodles though!). The keyboard cover is both good and bad - it isn't a "great" keyboard and can be floppy and awkward in certain positions, but the simple fact that it IS a physical keyboard beats an OSK by far.
In general I was less inclined to pull a traditional laptop out in many situations as I would a tablet, like waiting for a kid to get out of class. It is great for the random idea I got in my head I want to try out or jot some notes down, but for serious production mode it will never beat a desktop. Seated at a desk with peripherals such as mouse keyboard and monitor I'd say it is more or less equivalent to any other laptop.