I’m also considering getting a Surface Pro 4 or Surface Book mainly for digital sketching, rendering, and to replace my old laptop. I’ve only used both the SP4 and SB only for sketching in different apps but have really liked it. Specifically, Sketch Book felt great.
Initially, I was leaning heavily towards the $1300 SP4 i5 8gb ram model + keyboard cover which would total about $1430.
Then looking at the SB prices and specs, for $70 it seemed like going for the $1500 base model with i5, 8gb ram would be the right way to go even with less hard drive space . It doesn’t have the GPU in the base but for $70 you’d get much better battery life, a bigger screen, and a better keyboard and trackpad, oh and a cool hinge! I’m betting that hinge/release mechanism won’t last forever though I’m hoping Microsoft may allow the future Surface Book 2 base to be compatible with the SB like they have for the newest type covers and pens across the Surface Pro line.