Before the tune, I had this shifting issue - leaving the house cold about a mile away I had to accelerate to speed, a place where I was always part throttle since it was still cold. 'Stutter' sounds about right. The tune has resolved that, now it runs trough the gears quickly on acceleration (as an 8 speed should), it also seems to get to 8th quicker and hold it better.Do you have any updates on the "stutter on light load upshift when accelerating to highway speeds after sitting for a couple hours" issue? Has this issue come back at any point after installing the tune?
I got the W41 update and it definitely did NOT fix that issue. If the tune will fix it and I can avoid monkeying with the dealer any more on this issue, I may just have to purchase it finally, especially with it EPA compliant and a flash tool now.