If your equipment has a 4600 in it, I would stick with that option and not mess around with trying to run the 4640. Yes the unlocks that you buy with it do stay with the tractor for life, but so does the heated leather seat, xm radio, and powered mirrors. I would look at it more of part of the tractor and not a piece you put in the tractor.

The cost of the most expensive unlock on a 4600 (~$4,800) will get you every single activation for life with that machine. To do this with a 4640 would cost you over $10,000 in subscriptions over 5 years plus the $4,000 for the display.

I've used both the 4600 and 4640 this past fall, and while there were some minor things to get used to, the over all experience was much more desirable. I am excited to implement some of the new features deere has come out with recently for these displays.