Out of the 3, I like the Marquis and the Tropic Seas. Both have good insulation packages and self supporting shells. The quality of those are in my opinion, a little better than the Cal Spa. Not saying the Cal Spa is horrible though. All 3 use Balboa spa packs, which is a plus in my mind.
Can you sit in any of them to see how you fit? Is it possible to wet test any of them? This is a big purchase, you want to make sure that you are comfortable in the tub. You may find that one has a seat depth that you find more comfortable than another, that one may feel less crowded than another, etc.
Feel out the dealer too. Do they service in house what they sell? Do others have good experiences with the dealer? These are important as your dealer is your lifeline. Warranty is covered by the dealer, so you want a responsive, factory trained tech and if the dealer is not a good one, these become nightmares.
Personally, I have an Artesian and a great dealer. Granted, I have not had it long (3 months now) but my dealer has been responsive in answering questions and my one interaction with the service Dept has been spectacular. Prompt response to my call and they walked me through the process of getting rid of an air lock condition in one pump quickly and professionally. This is what you want from your dealer, no matter which tub you buy. I'm very impressed with the quality of my Artesian and use it 5-6 nights a week.
