It is a wonderful extension. I used it first on my Joomla site 1.0x, and when I migrated to 1.5.9 I installed the beta3 which worked incredibly well. One of the features I like the most is the ability to send (or not) a message to the user which includes username and password. Therefore it is very useful for resetting passwords, updating user information, and importing or reimporting users

This is what I had been looking for a VERY long time. I have been using PHPList because of the great functionally it has, but I had not been able to really use it with conjunction with Joomla's users.
It was VERY easy to install and the support is remarkable. I had my questions answered 10 minutes after I sent the e-mail. I am very impressed