If I had to be more mobile, I would choose rather a pocket that opens completely for quick strum without leaving the computer of pocket, very convenient but more expensive;
Another missing the point: a pocket to place the power cord, but it is the range above. If one is very mobile, well to make that choice and invest some more.
I have a "briefcase" computer, it is more convenient to use the computer, "secure" but however it is cumbersome ....