I think it is great, all the usual Windows items apply.
Specific to the SP3 Pro: use the SP4 keyboard, it is much better and is completely compatible; the dock is expensive and worth it: 2 display port connectors so I have the surface display, 4K monitor + 1K monitor attached working at the same time - Also wired Gigabit Ethernet; Magnet connector for the dock/power is super convenient; Power adapter has USB charging; I use the new Surface Ergonomic keyboard and a Logitech MX Master Mouse at home and the Surface foldable mouse on the road (best portable mouse I have used). I keep the surface on my desk so I can use it with my pen, I just flip the keyboard underneath it. On the road: the MicroSD provides all the extra storage I need (movies on the plane), and it has a real USB 3 port, battery life is around 5 hours, but better if you are only using it to watch movies or reading. Runs VMs effortlessly with i7 processor.
Biggest problem is power, sometimes it sleeps and won't wake up. Happens far more often than it should, but I haven't heard the same complain from people with Surface Pro 4s.
I recently got the Surface Book, and it's pretty fantastic. Both the keyboard and touchpad are great. I like the keyboard even better than my late 2012 rMBP's keyboard.
I have a SP3, and it's nice, but I didn't like using the type cover. I much prefer being able to keep it in my lap, with the screen suspended from the keyboard. I'm sure it works great with a dock, but I haven't use one.
