Totally personal opinion, but Id skip it. The best computer gains are done via dyno tune - but those run $400+ (and you'll have a hard time finding someone who specializes in your engine close enough to drive to - you'd probably have to settle for a LS shop with HPT).

The more common route is a mail order tune which is usually around $100-150 where they send you a tuned pcm to drop in, but I'd bet you'd pick up less than 10 whp off of it. Some of the tranny changes and stuff would make it feel a little sportier, but its not a major change overall.

 

Like Bumpin' said and I kinda mentioned, adjusting the transmission settings on the car are pretty much a bandaid. If there is a real problem, it will still be there and probably getting worse. As for "upgraded" computer, 99% of the time, it's just computer-based tuning (changing parameters in the computer). Unless you are going for some unique build, most people don't bother with aftermarket computer options (they cost a lot and if you get them, you NEED them to meet your objectives).
I have done some computer adjustments, including trans adjustments for the 3400 Monte (something I have offered as a minor service for people). On my 3400 Grand Am (different transmission), I adjusted the parameters in the PCM to improve it's shifting (I hated how it performed from the factory). After my changes, way more enjoyable when you romp on it. Better shift points, better up and down shifts. It is amazing what some tweaks in the PCM can do.

 

My 2007 Monte Carlo LT started doing this at 87K miles,. I took it to the transmission guy. He told me of horror stories of being stranded......
I decided to do a wait and see.... It's getting more often now.... I just rolled over 317K.....
I bought all the solenoids, figuring it might be a 'slow' one.... But, I have done nothing more than clean the screen and replace the fluid...
As expected, that made it worse....LOL I did that at 125K miles.....
Still wondering when I'll "be stranded in a parking lot in the snow."