Hello and welcome to the forums Thomas,
The chip inside a GB60 and a GT60 is exactly the same.
The are all mask xL31R (x = 1 to 4)
The GT simply has less pads bonded out to pins.
The MC13213 does not have all pins bonded out either and so is closer to a GT.
You can still use the higher timer channels and such, you just don't have the channel pins etc.
With the A versions of the GT they have actually cut down the die to more closely tie in with what is actually bonded out.
But I believe the Zigbee stuff still uses the old GB/GT (non-A)
