What is the difference between the FLEXiO 2000/3000 and the FLEXiO 2500/3500?

The FLEXiO 2000 comes with the iSpray Nozzle, and has a 2 speed switch. The FLEXiO 2500 is an upgraded, compact, lightweight design that makes it easier to handle when spraying.  It comes with the iSpray Nozzle, and a convenient side mounted on/off switch for one handed operation. The FLEXiO 3000 comes with a 9 speed setting X-Boost turbine, the iSpray Nozzle, and the Detail Finish Nozzle. The FLEXiO 3500 is an upgraded, compact, lightweight design that makes it easier to handle when spraying.  It comes with a 9 speed setting X-Boost turbine, a convenient side mounted on/off switch for one handed operation, the iSpray Nozzle, and the Detail Finish Nozzle.