I'd bought Saverio's original AutoGain plugin last year because a) it was ridiculously cheap and b) I wanted to help a promising new developer get launched. To be honest, though, it was pretty limited and I never actually used it beyond some initial testing.
 
However, there's a new improved version out today, AutoGain Pro. If you've bought the original, the upgrade is just 10 bucks.
 
It's been fancied-up and extended with a new GUI, relative gain adjustment and filters on the sidechain input. And one crucial feature that might turn it into a truly useful tool, and that's a negative gain option. IOW, instead of tracking the volume of a reference track, you'll be able to mirror the volume of a reference track (e.g. ducking).
 
I haven't bought it, but I do plan to try the demo. I think I've still got 10 bucks from the last time I turned over the couch cushions :)
 
 

I purchased it this morning but have not had time to install/test yet.

You guys must have completely missed my post...

What post? 
 
oops, I see it now...

rtucker55
What post? 
 
oops, I see it now...

Got it. This officially ruins my New Years resolution to not spend any money on software for one year. I made it one month.

clintmartin
Got it. This officially ruins my New Years resolution to not spend any money on software for one year. I made it one month.

Hi, my name's Clint, and I'm a plugaholic...

HI CLINT

Aren't we all???   Aren't we all???

I thought one month was pretty good! Upgrades don't count...new rule.

I like that new rule.

Sorry, Larry, I didn't mean to steal your thunder. But I see by the timestamps that we both posted at the same time, so it's a forgivable offense, yes?
 
Tell you what, you can be the first to give an in-depth review. Assuming Clint doesn't beat you to it.