I bought this presenter for an important presentation. First, the battery container wouldn't stay closed, so (being that it was an emergency) I taped the thing shut -- very bad engineering. Then it took me about an hour to figure out how to get the dongle to talk to the remote... yes I admit, if you precisely follow the instructions, it works. But it is not very natural and is something that I will have to read from the directions every time I need to use it. I don't know who thought this up.
Once you get the thing working, there are three modes -- and you have to explore each of these modes in detail to figure out what each of the buttons do. In the presentation mode (the one I wanted) I discovered that nestled snugly between the "next slide" button and the "previous slide" button is the "leave presentation" button. How stupid is that?... I must have hit the "leave presentation button" about a dozen times requiring me to go over to the computer and start it up again (yes, in principle I could restart it with the trackball which is impossible to use).
Finally, after an hour of using this thing you discover that the ergonomics are about as bad as you could imagine... I think I developed carpal tunnel in the course of a single hour. I'm sending this back to Targus. Just bought one from Logitech which works great.