Probably the best presenter on the market - but ...

Susceptible to interference ...
a) any other presenter of the same series!
Here in the university have some Studis same Presenter and depending on which channel the faculty presenter sparks, can with its own Presenter simply * play * and send commands to the receiver itself to the notebook. So already been one or the other presentation * * sabotaged - very bad!

EDIT: b) may seem a problem especially to be my presenter - as others complain about the high battery consumption, which in turn I can not confirm.
b) distance between presenter and the receiver!
If one is not more or less directly with the presenter in the direction of the receiver, it is more common that orders do not arrive and the lecturer / lecture so loses its momentum. The same applies to the distance between the devices. Since it should be possible mitterweile technically more!

Otherwise, in terms of functionality, material and design class.