Andy,
I read the app note and came away with a slightly different view than you did.
The app note is not warning against using PDATA. As a matter of fact it specifically (and correctly) states that PDATA is more efficient.
What it is warning against is setting the compiler options in the IDE to the compact model. If you use the compact model you are telling the compiler to use only PDATA and you are limiting your variable space to a 256 byte page. I don't know why they call it awkward but it is the memory model that is the concern not the data type.
Allen