You might look also at the high end Surface Pros. The Surface Pro 4 I think goes up to an i7 processor. I've had the Surface Pro 3 for about 4 years and it has After Effects loaded and performs pretty decent and that's with an i3.
The only drawback at least on this one is check the graphics support. I'm unable to take advantage of GPU and therefor can't use plugins like Mettle's ShapeShifer, FFP, etc. (a couple of my favorites). That may be resolved in the Pro 4 series though.
Eric