I am no expert, just another consumer like yourself, who had similar critical desires for our next spa. We owned used CalSpa for 10 years, until the wood frame rotted, otherwise mostly problem free. Three years ago, purchased a Costco Infinity Spa, which was a problem child and was returned to Costco last week.
We evaluated each local dealer history of customer service, selling their particular line of Spas, BBB reports, etc. Like you we considered the Costco's OC CalSpa Majestic 860 and the Evolution 80 by Strong......we just was not comfortable with buying another Costco "spec" Spa(Costco return policy is great, but do not want return a Spa every 3 years due to poor quality).
We considered Jacuzzi, Dimension 1, Hot Springs, Sundance, Maax Spa, Artesian, LA Spa, CalSpa,......either was not affordable, not impressed with quality or not comfortable with the local dealer.
We purchased a floor model Bullfrog 362 from a local dealer and have been really impressed with the quality and efficient design of the Spa. Our local Bullfrog dealer has been fantastic.
The one thing you may consider....Bullfrog has an agreement to have roadshows at local Costco Warehouses, which allows you to order thru Costco, with delivery and service provided by a local Bullfrog dealer. Otherwise, based on your list the new 2008, Marquis Reward seem tempting at $6,400, if you can live without "no options". I hope this helps.....Good Hunting.