I have Surface Pro 2 (2nd to top model, 256GB SSD, 8GB RAM) and I love it. I use it every single day at work even though it's my own personal device and I get some time on it most nights as well.
It's powerful enough to handle visual studio so I can write and run code on it. If all I wanted was a web-browser/document writer I could probably limp by with an iPad or something,. Surface Pro 2 is not only a replacement for my laptop, but it has equal specs and a much more desireable form factor. I can carry it around like a notebook, but it has a touch-screen, pen and ways almost nothing. It takes up almost no space on a crowded table in meetings.
Surface Pro 3 looks awesome, but I feel no envy. This is the way tech devices work. The very second you buy something it is on the verge of being rendered obsolete by a new model.