I have a very differing opinion of not taking it in the cockpit with you. I agree that it should not be your only source of navigation but I also think you should use all viable means possible to stay safe in the air and know exactly where you are.
I plan using Skydemon and then print it to a plog. I take Skydemon and chart and plog with me and match up the chart against Skydemon on a regular basis so I always know where I am even if Skydemon were to fail.
Why risk busting airspace or getting lost just so you can claim to be an expert with just charts.
Skydemon is an excellent navigation aid and well worth the money.