Sounds like you are second guessing your decision. Is that because the tub was more expensive? I have no experience with Coast, but Jacuzzi and Arctic are both in the upper tier of brands considered here.
I am a Arctic dealer, and the Eagle is a big seller for us. Very comfortable seats, and lots of jets and power. Did you wet test all of them? Are both dealers good local dealers? Where are you located/ I don't think you would go wrong with either the Jacuzzi or Arctic, but I am biased towards Arctic for obvious reasons. LOL.
Both spas are very comparable in size, features, and warranty. The Arctic has a few jets and is a couple of inches bigger and taller than the Jacuzzi. Let me know if you have any specific questions on the Arctic, and I will be glad to help.