I flashed my 2019 truck with the 91 Octane Performance tune from 5* today and did some driving, about 80 miles so far with some hard pulls and casual around-town driving. I will say there is a noticeable increase in power, in sport mode it's almost too quick to use for around town/traffic. It pulls really, really hard. So I am happy with that part. I am not happy with the transmission behavior right now. The truck seems to be constantly hunting for gears and seems confused. It will randomly slam itself into an inappropriate gear for seemingly no reason. About 3 times today it has gone completely out of gear and red-lined. There is just no rhyme or reason to the way it's shifting. Already working with 5* to see what can be done for it.