from pro to turbo = huge suction power difference and obviously more flushing power depending on the pump size of the Pro
The Storm is a great machine. Works just as good at 150 feet and its also lighter than the Turbo as it has one less vac motor.
I would recommend swapping out the 2 jet wand with the 4 jet Westpac, 1.75 inch wand. You pay an extra £150 (or something like that) but you get £150 and more worth of extra wand!