I use an old iPAQ PDA, velcroed to the control column, and Memory Map with full UK coverage at 1:500.000 and 1:250,000 (as well as 1:50,000 for the odd helicopter trip) on a set of 4GB SD cards. If I ever need to use it outside the UK, I can usually source in-date mapping one way or another. I can't say that I've ever felt the need for bells and whistles like planning software or de-clutter routines and my navigation is plenty accurate enough to do without airspace warnings.
I use the same device in the car with TomTom 5 and, in almost 10 years of constant use, WM has not crashed on me once.