I like the miniDSP a lot (I have 4 of them) - they are incredibly versatile and allow me to do almost anything I can think of with respect to tuning an audio setup.
However, they will occasionally mute or disconnect for no known reason. The device does not indicate which preset is selected unless you have it connected to a computer, which can be dangerous in a bi-amped setup. It is also very tricky to have 2 of them connected to 1 computer because the software is not able to maintain separate connections to each unit and gets confused. For this reason, as well as the form factor, they are no longer in use on my main audio system. They will still glitch on my desktop setup but at least it's not as critical there.