09 Transmission Issue
 

The car is starting to upshift roughly (downshifts are smooth as silk). It usually happens between 1st and 2nd, though occasionally on other shifts as well.

I really hate sealed transmissions, because I can't check anything, and I know nothing about the 5L40E. Is this something easy (fluid change), mildly painful (shift solenoids), or is my wife about to kill me for getting her to buy this thing?

Thanks in advance.

Sounds to me like the "Trans Control Mod." $500 + labor
EDIT: Now that I look at this I see you have an '09, Not sure if it the same as my 2010?