I like how easy it is for me as an admin to manage all my campaigns from one place! It's very simple but also powerful at once which makes this app great in terms of its flexibility (I can do almost anything with emails).
This program doesn't really offer much value outside being able send mass amounts of e-mails without having too many problems about performance issues etc.. If your looking for something more robust than what EMC offers then go elsewhere - otherwise stick to their product because they're good quality products overall! Sending out newsletters and general marketing material via bulk messages across our client base daily/weekly.