Hey jersiyindahouse, feedback here on the Buick Forum is a bit lacking, it seems to me, perhaps users are caught up in their daily lives.
Nevertheless, with my Turbo Regal, I found that the problem begins as the weather begins to warm up, with my measurements, at around 60F, it begins. What's the weather like where you are? I believe this is due to a poorly devised cooling system - radiator, transmission, turbo intercooler - which causes not just jerky shifts but also engine knock. I plan to install a transmission cooler and completely eliminate the radiator/transmission routing. I will also do away with the OEM intercooler - which I think is a piece of tish and replace it with an OEM Audi A4 or BMW 3series FMIC. I wonder if anyone else had noticed, it appears that the intercooler lines are criss-crossed. Yet, driving the car in the cooler seasons, the drivetrain system as a whole is best described as tight and flawless. Take heart, I'm sure a few simple modifications are going to put this right.
Yes, I plan to and will modify my car, warranty be dammed!