Congrats. We looked at the same model.
The Grand Cayman is basically a new and improved version of the old Artesian Emerald spa we have now. Same size, same layout, similar shell mold. Ours has DirectFlow but yours has more jets and one feature I really wish ours had: ABS bottom.
We're into our 17th year with it and we're pleased with the reliability. The heater needed to be replaced after ~10 years, that's it. We did replace a couple of the pillows for cosmetic reasons, but that happens with nearly every spa. We have suffered frame rot because it doesn't have a sealed bottom and snow & ice piles up around it. But now that they're sealing the bottom with an ABS pan, I'd have no qualms about buying another one. We really like the open layout and the pumps are quiet and provide good jet pressure.
Unfortunately, our old dealer dropped Artesian for Master Spas a few years ago
and the dealer who picked up Artesian is unresponsive. We could reach a receptionist, but couldn't get the sales guy to return our calls. I guess he must be happy enough with the business he's already done this year. Or something. Anyway, that means we're not buying Artesian this time but I would have been happy to.