I had a Sta-Rite dual speed pump (1.5 HP high, 1/2 HP low). The low speed didn't really work that well. In many cases the flow was so low the pump lost its prime and stopped working. I eventually opted to keep it running on high whenever I operated it. Plus, installation was an annoyance as it took us a few tries to find someone that could wire the thing correctly. Even with Ben's explicit instructions I got a few puzzled looks. The electrician finally figured it out. Your mileage may vary but I won't buy another 2 speed pump going forward.