I use LISA daily. I get a lot of mail all day long while working and LISA helps me know whether new mail needs to be viewed immediately or can wait. That it uses a pre-recorded voice means that the voice quality is excellent. On the other hand, it doesn't allow for customized alerts and you need to be creative about using its pre-set messages. Setup can be a pain because you need to enter senders manually. But all in all, I am pretty happy with LISA. I would like to see auto-integration with Address Book and an option to allow custom messages, even though they would use a computer voice.