Can anyone explain the advantage of upgrading the M600 to the A3 package?

Do you mean just adding the extra A3 GPS pucks and IMUs for the redundancy?

I'm very interested in that too!

The M600 uses the A3 as standard with custom FW, what you can add is the IMU kits for redundancy turning it into the A3 Pro setup

As standard the A3 uses its internal IMU with in the FC, Adding 2 Pro Kits will give you 2  external IMU's, 2 additional compasses and 2 additional GPS for redundancy switching.

In theory its not going to bring much addition stability other than its likely it will default to one external IMU over the internal one but it will give much more redundancy in a failure situation.

If your looking to real stability you need to be looking at the RTK with the Pro Kit.

DJI-Jamie Posted at 2017-5-31 19:56
Do you mean just adding the extra A3 GPS pucks and IMUs for the redundancy?

yes.      

Mad_Angler1 Posted at 2017-6-1 12:07
The M600 uses the A3 as standard with custom FW, what you can add is the IMU kits for redundancy turning it into the A3 Pro setup

As standard the A3 uses its internal IMU with in the FC, Adding 2 Pro Kits will give you 2  external IMU's, 2 additional compasses and 2 additional GPS for redundancy switching.

Thanks