Take a peek at the overhead picture of the spa on the SD's website.
In this particular spa, there is a lounger. That's one seating position. The lounger and the filter bay occupy two corners of this spa. The other two corners are seats, so I'd say there are 3 "main" seats.
Between these three prime seats, are 3 more seating areas. One looks like a cool down seat (no jets) and the other two look like they have one or two jets.
So I'd say a maximum of 6 occupants, everyone would have a seat.
Weather or not you'd like the mid seats is a matter of personal preference. We use the ones in our spa (Optima) quite often- sometimes you just want to sit and relax, without the jet action.
Brewman