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I was actually suprised that the Marquis was as expensive as it is because it is actually a little smaller than the Sundance/Caldera (both 7' 5" square vs. 7' square and 485/500 gallons vs. 370).
I think this board has changed here of late ...I am not going to try and say what I feel is the best but some the things written in this thread are simply inaccurate...I recently had the chance to look at several different makes in the last thirty days and I think if you look at all three tubs and if you can take an 8 year old with you and in about 10 minutes they can tell you which of the three is the better built spa....its not tough to see when looked at with eyes wide open.....