The polarity switching makes this the most versatile footswitch around. However, it would have been great if it could also function as a latching footswitch. Instead you have to purchase a FS-5L to do that. All of these FS footswitches interconnect, which is very cool. However, the cords cannot be bussed so you will have a separate cord for each switch. Also, the aluminum edges are sharp and will make quick work of your gig bag if you travel with it.  Additionally, the pedal surface itself is slippery and a relatively small area.  This makes it better as a on-off or tap tempo pedal than a sustain pedal.