Hi Joel,
Arctic is a Canadian brand, and honestly they're a mixed bag. They're not on my recommended list.
The shell is good, simple as that. The acrylic itself is pretty much standard across the industry, but Arctic backs it with a good heavy fiberglass layup, and it's a true self-supporting shell. No complaints there.
The jets are another story. They're Rising Dragon out of China, one of the cheapest jets on the market, with thin plastic bodies. Arctic puts their own label on them, like they do with a lot of their components, but underneath it's still Rising Dragon.
On plumbing access, which I know is your big concern, this is where they fall down. They don't clamp their plumbing lines, which raises the odds of a leak in the first place. And for access they use small removable panels that work more like portholes than real access. If your leak happens to be right behind one, great. If not, it's a nightmare.
Their saltwater system is automated, and that part is good. It works a lot like the Master Spas system, which is the only other on-demand system out there. The catch is that Arctic runs a much higher salt level, somewhere around 40 to 50 percent higher. Bigger problem: Arctic designed their own heating and control pack to go with it, and it was a disaster. They went back to Gecko controls on everything else, but if you choose their salt system you're still stuck with that proprietary pack. High failure rate, questionable parts supply, made in China somewhere. That pack pretty much undoes the benefit of the salt system.
The Forever Floor is interesting, but it's mostly marketing. It's pressed fiberglass, and fiberglass doesn't love living in a wet environment unless it's fully sealed. On a boat we gelcoat everything so water never touches the glass. Arctic does protect it to some degree, and then they screw mounts and supports right into it, so now you've got penetrations in that fiberglass. I'm not saying the floor will fail. It won't. It's just over-engineered for no real reason. A good ABS bottom pan already is a forever floor. ABS doesn't care about water and will outlast the rest of the tub.
Now energy efficiency. Arctic uses a perimeter insulation system. When you open the access door it looks impressive because the insulation on the cabinet walls is thick. But slide your hand in toward the back of the shell and you'll notice it's pretty thin there. Perimeter insulation is not better than full foam. The R value is lower, and there's no way a lower R value system beats a higher one. Simple as that. Two or three inches of high density foam on the shell isn't going to compete with a full foam tub, not even close.
They'll also talk about reclaiming motor heat, but every tub does that. On a full foam tub, the equipment bay up front has intakes that feed the ozone system and the venturis on the jets, so heat is actively pulled out of that cabinet and put right into the water. A perimeter system collects that heat passively, through the shell and the plumbing. The shell has high density foam on it, so it won't absorb much, and a lot of that heat just goes out through the cabinet walls. A perimeter system is the cheaper way to build a tub. Full foam is the gold standard.
The other thing to know right now is price. Arctic builds in Canada, and with the current trade fight, Canadian goods coming into the US are getting hit with tariffs. That cost doesn't get eaten by the manufacturer. It goes straight onto your price tag, and that's a big part of why Arctic pricing is so high right now. You're paying a premium that has nothing to do with the tub itself.
I did a review of an Arctic Spa a while back, and everything in it still applies to their current lineup:
https://youtu.be/FHgXSlKzPAI?si=qqboOGGqaRe8GVF3
And here's a video on how the different insulation systems compare:
https://youtu.be/4XhgwOQKQFs?si=5M6mO-CDpvPMnKlO
So you were on the right track with Master Spas. Happy to dig into specific models with you if that helps.
Chris