I've spent way too much time playing with gadgets for aviation use, and have concluded that the only way to do this is
- use a nice lightweight laptop for all ground based tasks (plenty of choice there, from relative crap @ £200 to top grade slick corporate hardware @ £1500)
- use a tablet computer in the cockpit, if you want a GPS moving map or if you want to display IFR approach plates
Beyond this, the discussion gets quite wide ranging.
The main issue is that nobody has produced a convertible laptop/tablet (e.g. the nice
Fujitsu P1510) with a sunlight-readable display. For marketing reasons, the special LCDs are offered only on £2k vertical-market tablets such as
this, or on very heavy mil-spec tablets costing £3k plus e.g.
this. Back in 2004/05 I tried using the xplore
ix104 tablet but the size/weight was silly.
I don't use a PDA - screen is too small. It is OK for w&b calcs... not for a moving map.
But then I have a panel mounted GPS. Somebody who does not have this has a requirement for ground based flight planning, plus a decent moving map GPS for use airborne. There isn't a single device currently which does both well.