The Surface is pretty well protected by the Touch Cover but that’s still not full body protection and if you want to throw your Surface into a bag you’ll want the back and edges to have some coverage. After scouring the net I ended up buying the KaysCase Leather Sleeve from Amazon for $18 shipped. I wanted something that would give me protection but it would still allow the Surface to easily slide out and it would be out of my way. And this one fits the bill. The Surface fits well even with the Touch Cover on and there’s an external pocket that’s nice to drop a hotspot into. The only con is that it leaves one edge slightly exposed with the edge of the Touch Cover aligned with the edge of the case and the actual Surface edge just covered (I sort of wish it were a top down envelope style like this but this isn’t fitted for the Surface).
Overall I like it. It’s sized for the Surface, is relatively inexpensive and looks nice. And they’ve added colors so it now comes in black, cyan and magenta.