The problem with a PDA is the same as the SUV's.
Its multiple use feature is its drawback.
If I need to carry lots of cargo, I use my Express van. If I need to go somewhere I use my Corolla. Some people buy an SUV because they feel they might use it to haul a house when they will never get to do so, or maybe once or twice.

That is
the waste.
I still prefer dedicated devices optimized for a specific use.