The Beachcomber 740 is one of the most comfortable, therapeutic spas on the market.
If therapy and energy efficiency is paramount, I would also seriously consider this:
Hydropool 638 This also has a single lounger with slightly more therapy in the platinum edition along the similar price point you're considering. It's also more "feature rich" and gives you far more choices than most manufacturers. The self cleaning floor system and superior insulation technique gives the end user a very low operating figure while addressing the cost of possible future repairs by not foaming around all of the plumbing like Beachcomber. I'm sure you will be very impressed!
I'm not familiar with Artesian nor have I sat in one though we have a couple owners on this forum that could shed far more insight on them than I certainly could.
Wet test the spas you are interested in as this will tell you everything you'll need to make this big purchase right for you and your family. Good luck and let us know how everything goes.
Steve