Couldn't agree more. The Store app has always consumed the most battery on my system. Need a quick easy way to turn it off when not being used as it still seems to be doing stuff. It's also huge as apps go.
In our experience, battery life is another big step forward, especially in the i5 Surface. Our battery benchmark (streaming video with brightness at 75 percent and no major background apps running) has the Core i5 Surface Pro 4 only dropping 9 percent per hour – the same as the Surface Book. The Core m3 model dropped 11 percent per hour (another reason we think the second-tier model is a better choice).
Both results are improvements over the Surface Pro 3: when we reviewed it in 2014, it dropped 16 percent per hour in the same test.
Percent Battery usage per hour during test:
SP4 i5 .. 09%
SP4 m3 11%
SP3 i5 .. 16%