Gyro Drifter
You reckon your setup could substitute a handheld garmin unit ...
I reckon so.
I use the PDA and PocketFMS on long trips (hence the need for a spare battery).
Don't get me wrong, a dedicated GPS box has its' place, and it's very convenient to just press its' on-switch and away it goes, whereas the PDA method does require a few button & screen presses.
But., for around 1/3 of the price of a Garmin 296, I reckon I've got most of its' features and more versatility.