There's more to the Memory Map version than just a printable map. A couple of clicks gets you a line on the map - just another click and drag to insert waypoints. You get total and leg distances AND true tracks. Absolutely brilliant for planning without having to spread a map all over the living room floor and getting ink on the carpet etc!
Once you've chosen your route, simply print out the necessary sections on A4 in landscape; I use an A4 board for longer navs. You can scribble headings, times etc on the printout, then any ATC stuff, wx etc. Then throw the sheets away at the end of the flight; they've cost a penny or so to produce!
I've looked at Skydemon maps and I do believe they're not 'official', so you still need to buy the relevant 'legal' chart.
Best 20 quid I spend every year on flying...
Cheers,
The Odd One