How long have they been in business and how long have they sold the brand you are interested in?
Stay away from dealers that consistently change the brands they sell. It would also be helpful to know why they chose to sell this brand.
Are they willing to come to your house to provide a site inspection at little to no cost?
Do they service the products they sell?
Great dealers stand behind the products they sell. Be sure to find a dealer that provides year around service so you can enjoy your hot tub in complete confidence.