I own a J-480. I've recently posted a review in the review section as well. I've had the 480 for 4 years. Therapeutically it's great. My model is loaded with waterfall lights and stereo. Two things I would never do again: get a stereo in a hot tub and buy a J-480. (or 470). My complaints are strictly on the maintenance and repair of the 470/480 models. If anything fails, you must deal with Jacuzzi for parts due to the case design, especially replacement covers. Get a Jacuzzi with a flat edge top! Replacement covers from Jacuzzi are over $1000 (in Canada) and cannot be made aftermarket (they can, but they all fail to fit due to the complex case design on the 470/480).
However, the performance of the operating tub is great. The jets are plenty powerful, nice air control, and relatively comfortable seating. They make a decent tub, until something goes wrong.
I had previously owned an Arctic Yukon, but opted against them when they off shored all their major components.
After owning 2 tubs, I know how I use them. I would focus on the specific seat configuration I want for the primary users (myself and my wife). If there are 2 seats with the proper jet configurations to deal with our aches and pains, that's the manufacturer for me. What the other 3-4 seats do, the lights sounds and everything else would now be secondary. Standard dimensions and long term ownership would also be factors in my next decision.