If there is a shudder...and you list a 2010, there was an update to the T/C lockup points at low load / rpm / speed scenario that GM updated. It is possible that your are downlevel on your GM code version.

That said, the right custom tune will bring you up to date as well as "improve" on what was stock.

AFM when done right should only really be heard through a different exhaust note and only felt in your wallet by potentially getting better fuel economy. There is a person on this forum, pir4te, down in AU that is doing some great things with AFM & VVT on his Holden. Good power and good economy and many trouble free miles.

Agreed! Don't keep any of it its useless.

THIS!

Tune it out.....you will feel it and defietley hear it. When you get on it sometimes the car will at an rpm to engage it and would fall flat in its face. Aftermarket exhausts makes it worse.