Just to change angles a little on this search for excellence at reasonable cost.
Intead of spending on another new 'screen device, is there any simple (for me !) to use compatible with WindowsXP software for my ready to hand notebook ? My efforts in attempting to download even portions of a chart to experiment with have failed !
[Toshiba NB205] with 10 diagonal screen & >8hrs battery life:-
I'm thinking of, say, some form of GPS gizmo and a 1/4 mill SEast GB chart from somewhere, so at least it plots my track onto a CAA type chart display.