Passport America, worth it or not?

It's a pretty darn good deal if you can use it. For us, and we may be in the minority here, it just didn't work well. In our case, there aren't many parks close by or close to where we frequently travel. Additionally, most of the parks that participate have their own set of rules for booking and those can be hard to find for each place, change frequently, are different than stated on the PA web page, or are dependent on some strange factor that doesn't present itself unless you dig for it. Too much hassle for weekend warriors.

As was stated, if you travel during the week or spend a lot of time on the road, it's a no brainer for sure.