my son fly fished out of his old sytyle seat PA 14 with little problem--standing.
he is now fishing out of a 2013 PA14 and says the difference is night an day. he says he can move his feet at will to adjust himself. and with the seat raised in the new boat, he can lean slightly against the seat for additional balance. i dont fly fish, but i do stand a lot to fish. we fish the flats for redfish and standing gives a much better prospective. i love the ability to stand in center of the boat, rather than forward. one would think that since the PA14 is a few inches wider, it would be more stable when standing, but not that he or i have noticed. i assume its the sponson design hull the PA boats share, that gives them a 'wide feel' in the water.
as for maneuvering, we have not noticed a difference in either boat. each one has its own 'personality' in the water and no two handle alike, but we have not noted a recordable difference.
for mobility when standing, again we fish in shallow water, we use these.http://www.accentpaddles.com/transformer-versa.php
whether as a paddle or a pushpole, it makes life much easier. and it can be converted to a stake out pole as well.
Thanks Drew, I spend almost all my fishing time standing in my Commander140 so I known were your coming from. The reaason I'm considering the PA is because of the fixed feet position that occurs when your feet are in the sponsons that the Commander also has. The flat standing area with the ability to flip the seat up for more room make the PA real attractive. I will occasionally fly cast from the captains perch on my Commander while sitting, but it just is not the same as standing.