I had my auto update done recently at my 10,000km service. I'd previously had the new tail shaft installed too (around 4,000km). 2016 Hilux (March) SR Diesel 4x4 Auto.
At first, driving around town (small country town) I didn't notice much difference. But then I went on a trip to Adelaide and on the highway saw an amazing difference!
Previously it wouldn't hold 6th in cruise unless you were going downhill or on flat ground - the slightest hill would kick down to 5th and 4th. It was constantly doing it, and driving me nuts, to the point of me turning off cruise a lot of the time.
But now it even holds 6th going up slight inclines! In fact some hills if they get steep it will still kick down (smoothly too I might add) then kick back up to 6th as the incline gets less, but I'm still going uphill!! Ie it's working as an auto should.
And I know this is subjective, but I think fuel economy is a bit better too. Previously I would average around 10l/100km doing a trip to adelaide. The most recent trip was down to 9.0! But maybe I just had favourable tail winds or something
Anyway I think it is definitely worth doing - I just wish Toyota would be a bit more proactive and get their dealers to do this to every hilux that comes in rather than waiting to be asked about it.