We are using cPanel Extended for about 3 years now. Because we are a small web development and hosting company in Belgium we wanted to give something easy to our clients. With cPanel Extended our clients can just login in their client area and modify all the settings they want. The can create, delete or modify email accounts, ftp accounts, forwarders and so much more.
Most of our clients never use cPanel, the all do it from the their client area.