replace Heidenhain with Gecko?

I am looking at a Bridgeport CNC mill (with servos) that has a Heidenhain controller with Z axis out. I have seen a few similar machines that use steppers and Gecko G203V drives. The mill I'm looking at has servos and I am thinking about replacing all 3 Heidenhains with something like Gecko G320x or G340 drivers. Is that a reasonable thing to do? Will Gecko drives handle the Bridgeport servos? And it would appear to be a pretty straight forward replacement - or am I being too naive? thanks Chuck