Mine was:
Makita guide rail: you can use the makita and the festool saw on it, costs less.
Festool guide rail: you can use the makita and the festool saw on it, costs more, and you lose the anti-tilt feature of the makita saw when used with the festool rail.
Anyway, I got plenty of festool rails and saws at the moment. I will however buy another long festool rail when the parallel rip jig ends up in the stores around here.