On mine, the speakerphone is essentially unusable, because the sound level rises and lowers constantly. Even when I am able to figure out what the other party is saying, they can't seem to be able to understand me.
This problem also seems to exist on the handset, but to a lesser degree.
Problems can be slightly reduced by turning off and on the handset, which gives you from a few seconds to a few minutes of almost dependable use; but the gremlins then come back.
Please note my problems are related to the US version of the sw. If there are Euro-side problems, these may be different.