I use a Surface Pro 3 i5/8gb/256gb for web development & managing engineers. It handles pretty much anything I throw at it, including virtual machines. In my home office, it's docked to 27" and 23" screens and a bluetooth mouse & keyboard. And when I'm done with work, it's a great machine for social media and other things, even some gaming.
The main thing I'd point out is the Surface Pro 3 has a problem with heat, and will sometimes need to throttle the CPU to cool itself down. I hear this is handled way better in the Surface Pro 4 and the new Surface Pro.