http://glassbox-design.com/2010/sicce-psk1000-psk600/
These guys say that they have "fewer" startup issues. Most places say that they are much better now because they have the circuitry for directional startup. If that problem is gone that pump will be great, the 2500 I have is a beast for air draw, and other than start up's it's had no issues. So if they only improved the start-up in the new models I'd be impressed.