Resurrecting this old thread, as I'm just looking into P1 versus GT1 myself.
From what I've read, the more expensive P1 comes with a less-adjustable pedal deck, albeit more *easily* adjustable front/back.
Does anyone know why they took that (apparent) step backwards in the design? Does anyone know if it's possible (e.g. $$$) to get them to combine the two designs, keeping the easy front/back adjustment (so that my nephew can easily hop in and get comfortable), whilst enabling the higher deck setting if we want the open-wheeler-style seating position with raised legs?