The 900W model has higher pressure (3300PSI) for a smoother finish, more nozzles & accessories, and is lighter (10.38kg)—better for home use and better value.
The 950W model has higher flow, heavier duty for commercial/frequent use, but fewer accessories and heavier (13kg).
For most users, the 900W is the better choice because of the full accessory kit and similar performance.
By vevor