Was the Vanguard over filled for wet testing?
Not the end of the world that they have an outside company certified for service on the Marquis side. If that is the only issue with the dealer and you prefer the Marquis hot tub I think Marquis would be the way to go.
Dealer is always very important.
You need a hot tub that works for you, not a compromise.
thanks,
Porter
P.S I sell Hot Springs.