It is excellent and a great step forward from the iPaqs. Points additional to those already mentioned:

Choose your waypoint file carefully so that waypoint names start with abbreviations which will be helpful on screen. If you are like me you will take advantage of the ability to have landables showing at higher zoom levels than other waypoints. As someone else has implied, it is useful to allocate actions to navboxes, so that you can go straight to often used functions without having to go via the menu. For example, I use one navbox to toggle between the two map pages, and another to go straight to the task page.

It is particularly nice to have a whole world base map already loaded, and to have lifetime software upgrades included.

One thing I don't like is use of a micro SD card. For any file transfer needs I prefer to connect the device by USB to my laptop. The device itself does not have any file management software on it. The internal GPS is welcome as a backup, but this is not the best device to choose if you do not intend to connect to an external GPS source.