Recommendations for trans tune

Looking for recommendations on a transmission tune on our 15 Denali XL (8 speed). On the first 1-2 shift every day it is very rough. Other than that, it shifts normal. After that, it shifts perfect the rest of the day. Who would you recommend for a trans tune to try and remedy this as much as possible.

The favorite part of my tunes is in how the transmissions operate. @BlackBearPerf has tuned 2 of my 3 trucks so far. Will be doing the 3rd soon.

x2 @BlackBearPerf is the way to go.

X3. BlackBear Performance is definitely the way to go.

I don't think blackbear can do 8 speeds.

I have the 8 speed and understand what you are saying. It doesn't bother me, so I don't want to go down the rabbit hole on tuning. What I can say is that if you don't service it every 40k, and have an intermittent CEL light for trans temp failure, you will get harsher shifts. I replaced the trans temp harness with new fluid and filter - it's back to butter.

Currently at 163k.....still going strong. Serviced every 40k

A tune will be accurate for a healthy transmission. Yours is a little off the mark so a tune could make the symptoms even worse.

First, get a fluid flush and then drop the pan and clean it — checking for debris — and change the filter. Fill it up with the latest Dexron and drive it.

You may find your symptoms have disappeared. If they haven’t, you can do a custom tune that will compensate on the wear you have, but that is different than a box performance trans tune.

Performance trans tunes are done to optimize shift points and clutch behaviors during heavy input loads.

See if you can get yours healthy again and then get a performance tune, such as Black Bear. Otherwise, you can talk to performance tuning shops and have them do a custom tune to compensate for whatever behavior your trans is doing after the fluid work.