Research the dealer. After the sale support is equal in importance to a quality brand up front.
Jacuzzi, Bullfrog, Sundance, Marquis, Hot Spring, Caldera, Artesian would all be on my shortlist as a dealer choosing to represent a brand. Due to quality, but support the manufacturer provides.
My take is that a great dealer can even make a okay hot tub seem great. By contrast, a bad dealer can make a great brand seem terrible.
Wet test if you can, as that helps significantly.