I have a Surface
Pro 2 (256GB so I could get more RAM) and it works well enough for quickly viewing and bringing down data, I dont edit with it. I have a whole different rig for that. DaVinci slows this system down to a crawl, and sometimes bugs out canceling the render. I dont render on this machine any longer.
Now, by the time you get enough hardware into that SP4 (i7 and large SSD) you are spending as much if not more than some of the top end 15" gaming laptops with much better hardware for rendering and processing. I love the size and form factor of the SP4 and nearly bought one for this purpose, but could not, for the price, justify it. Again, I like the SP4 format and what it can do.
I got the following for $120 more than the SP4
17.3 inch 4K UHD (3840 x 2160) IGZO IPS Anti-Glare 400-nits Display
NVIDIA(R) GeForce(R) GTX 980M with 8GB GDDR5
Intel(R) Core(TM) i7-6820HK (Quad-Core, 8MB Cache, Dynamically Overclocked up to 4.1GHz)
32GB Dual Channel DDR4 2133Mhz (16GBx2)
256GB PCIe SSD (Boot) + 1TB 7200RPM SATA 6Gb/s (Storage)
Intel 8260 2x2 802.11ac 2.4/5GHz + Bluetooth4.1
Windows 10 Pro (64bit) English