Agreed with other's statements that the transmission is problematic. In my experience with this transmission, and a very similar version in my Traverse, there are two common issues.
1. Shift flare, which is a delay between when the transmission lets one gear go and then engages the next. This usually happens between 2nd and 3rd. Simplified, the pump component of the torque converter isn't providing optimal pressure for the shift change, so the trans waits for pressure to get there and leaves you sitting there feeling like you're in neutral for fractions of a second. At the beginning, it only happens at very specific combinations of rpm's, speeds, throttle position, etc. On my Traverse the problem has gotten worse over time and it has become very hard to accelerate without the flare. Feathering the throttle just right before the shift is the only way I can avoid it now. A torque converter replacement is likely a forgone conclusion on the Traverse now.
2. Second issue is the identity crisis that the trans experiences when it doesn't know what it wants to do. Should I stay where I am, upshift, downshift, mens room, ladies room??? The 4 speeds in my Pontiac Grand Prix's had similar issues to a lesser degree. It's like GM took the same design and then threw in 2 more gears to ensure occasional chaos. On both vehicles, I eventually adapted my driving style to the trans (and lightened up my lead foot) and now I almost never have these issues. Only occasional thuds when slowly slowing to a stop up a hill. Older GM trans (25+ years old) used to adapt to me and I drove how I liked. The newer ones increasingly require me to adapt to the trans.
I am very interested in experiencing this engine in the Camaro to see how the experience differs with RWD and a more capable trans.
