My programmer recommended Autoresponse Plus earlier this year... ... The very next week, the site was down. Now it's back online under a new owner. Is it worth almost $200 (and Alex, does your plugin support it still)?
My 2 cents I have the ARP plugin. It was quite a while ago that I installed it. But if I remember correctly, it took a little more work than the other plugins. ARP is pretty darn powerful software. Unfortunately, documentation is not their strength. So in order to leverage all of it's functionality you will need to feel comfortable with rolling up your sleeves and playing with it a bit. I have not looked for this type of tool recently, but if I need to obtain a solution, I would probably buy it again.
Yes, this software is supported by aMember, but to be honest, I'm not happy about level of integration and complexity of setup this. aMember has some functions of ARP implemented inside. Have a look - may be it will be quite enough.