Hi, although Marquis has re-designed their Spirit model in 2012, I can tell you that I love my 2011 Marquis Spirit that I have now been enjoying for a year and several days. There are quite a few differences between the two years models though. The in line sanitation system is not a 24/7 circulation pump. As a whole, the Marquis don't offer circulation pumps (that I am aware of anyways). They do have quite a bit of information on their website, and you can also pull up the owners manuals to get more info on how each system in their tubs work. As far as the number of filters, my 2011 Spirit has 2 filters, but I did see that they reduced that to one on this years model. Also, just to let you know, the smaller amount of water in the tub, more monitoring the water will need. Not a bad thing, just want you to be aware. (My Spirit is listed at 165 gallons, though I know the new model is larger, which would help in the maintenance).
As for the Jets, I really enjoy them in my tub. I have been in other tubs and end up feeling a bit bruised if they are at full strength, but in the Spirit, they are strong, but not abusive. I can enjoy them on low speed or high, and feel relaxed, not as though I am fighting with them.
I did try the jetsetter, and it just wasn't a good fit for me. The quality was wonderful, and it came in as #2 in my search, but I didn't fit well in it, and really didn't care for the moto massage at all. I believe that you will know the right tub when you try it, so be sure to wet test any tub you may have an interest in.
Good luck in your search, and pay attention to your gut instincts too. Go with what is comfortable, both in the tub, and at the dealership. I visited 7 different tub dealerships in my search, and several I felt very uncomfortable at, while others were very welcoming and seemed genuinely interested in my search, though I will say that I never received the "Car Dealer" attitude from any of them. Most sincerely said that it is a very personal decision, and they would not pressure anyone into buying what may not be the right tub for them.