The first time I tried making it following the suggestions for the measurements, my pieces were too small. I ended up adding extra to the cutting dimensions. You might want to add an extra 1/2 inch onto your measurements just to be on the safe side.
I used flannel for the lining and it makes a good protective case. I do wonder about using fleece as that would also add thickness to your case and possibly make the case too small. A low loft fleece might be a better choice.
The directions were easy to follow and the pictures clarified each step.
The next time I make a case though I think I will modify it so it has a flap over the top and a velcro fastener. This case isn't the easiest to manipulate with buttoning and unbuttoning when you are going through security at the airport.