Cal Spa is pretty meh, if you ask me. They aren't the worst but there are other brands I would pick over them. Artesian is good. Marquis. Bullfrog. They get some hate, but I do like Hot Spring/Caldera and Jacuzzi/Sundance, though I've heard Jacuzzi brands have been cutting corners, specifically in the insulation department.
As noted above though, a good dealer can make any hot tub a great experience. A bad dealer can make a great hot tub, a terrible experience. Go with a reputable dealer that has a spa that fits your needs and budget and don't fret too much on the brand. If they are a reputable dealer, they probably have a decent brand and will take care of you.
An example of this is that Master Spas makes a pretty good hot tub but their dealer network/show sales are trash. Just look at all of the complaints, bbb reviews, etc. It happens all of the time that something isn't right on delivery or shortly thereafter and you'll see people talking about damaged covers, broken panels, incorrect spa or options, and they sit for months and months with no resolution. A good dealer will make it right, with no hassle, and quickly so that it never escalates to needing the BBB or yelp to step in.
Look at the links below for different Master Spas companies and see for yourself. Most of the problems are a direct result of poor support and shady sales stuff. Every spa will have problems, but not every company allows it to escalate to bad reviews/complaints.
https://www.bbb.org/us/in/fort-wayne/profile/hot-tub-manufacturing/master-spas-0352-10011179/complaintshttps://www.yelp.com/biz/aqua-spas-fort-collins-3https://www.yelp.com/biz/master-pool-and-spa-minneapolis
