Only downside is that it is self-calibrating, so if you have a joystick pot that sometimes jumps to very high (or very low I suppose) resistance, it will scale the axis to that very high value; calibration on the PC in that case will give you terrible resolution (since it is quantized before being sent to the PC). I suggest cleaning the pots with DeoxIT if that happens.
Only downside is that it is self-calibrating, so if you have a joystick pot that sometimes jumps to very high (or very low I suppose) resistance, it will scale the axis to that very high value; calibration on the PC in that case will give you terrible resolution (since it is quantized before being sent to the PC). I suggest cleaning the pots with DeoxIT if that happens.