I was not very impressed with Get Response at all. You cannot import your existing leads (unless the customer reconfirms which is unlikely) and the purchased leads that Get Response offer are very expensive. I havent used Aweber, but I presume they are similar?

So I settled on Smart Autoresponder via Listbuilder which is very simple to use and has far less confusing options (that you dont need) than other autoresponders I have tried. You can purchase leads from listbuilder at reasonable prices and guess what, you can IMPORT your existing leads WITHOUT customers having to reconfirm!

The Autoresponder is actually an addon for the main list builder lead packages, I'm not sure if you can just use the autoresponder without purchasing the leads, but it works out well for me.

If you are interested : http://tinyurl.com/472hc7

thanks