I think the control interface is terrible. It is not intuitive at all. I have to get out the manual every time I want to do something. The manual is also terrible. Very hard to figure out what buttons to push from the illustrations.
The other thing that I have a problem with is me having to add insulation for winter. They don’t give much direction for it either. How about a youtube video showing exactly how to do it. Personally, I would rather pay a little more and get something that is ready to go from the factory.
So my suggestion would be spend a little more on the interface, add more buttons, etc. and insulate for -20 F° at the factory. Yes, you will have to charge more but not that much.
I also dont’t like the jets coming on unpredictably when I am in the spa need a better way to control them than using the Hold option.