I agree with Larry, except I do think it makes a difference.
Marty, just step back to a 1.75" wand, it's a whole lot better than dropping to a 1.5", and that superflex 2" hose shouldn't be any more stiff than most 1.5" leaders.
If you do opt for a leader, I'll send you one of my Cobra lead hoses to try out, it starts out 2" and Sloooowly tapers to 1.5", very good on airflow.
It's only avail in the carwash grade right now, working on the polymer to make it higher heat with my hose guy.
As for upgrading, are you happy with your production and dry times...then screw it, stay with the machine you have, besides you already have a vac booster, if anything a mainline hose upgrade to 2.5" from van to door would give you the most bang for your buck.
Your unit is plumbed 2.5" from blower to tank...right?