Hi Marie,
I work at a hospital that has the Phillips ST80i machines, they are very nice to work with and I prefer them over any machine that still uses long cords to connect the patient to the computer. I love them!
The issues with connection are minimal, turning the wifi button on and off usually does the trick. You need to be careful about how you clean the wires and box as to not soak the ports in cleaner but other than that, the machines are perfect and zero issues with artifact (that aren't fixed with proper placement, scratch tape, etc).