I like #2 for a multitude of reasons:
The pool is less cluttered looking than in #3.
Leaves more open space than #3 - much less constricted.
You already have one sun shelf. I get the idea of having separate gathering spaces, but the spa will also be a gathering space. Adults in one corner, kids in the other.
The sun shelf is more versatile being mostly square. Two or three lounges can face in either direction. In #1, makes them tighter if they face the left/right at the head/foot areas. Back in my tanning days, facing the sun was very important for the optimal effect.
The L-shaped seating area that the benches create will be great for several people to gather on and be able to face each other while talking. The benches in #1 give you seating space that face to a less desirable area for conversations in the pool. Also, longer more continuous bench space is fantastic for the young kids not yet swimming. They run end to end while their parents hopefully are paying attention.
Will there be just one light in the main pool? On #3 there are two lights, but one of them disappears on #1 and #2. I'd say you will want two lights. Sorry if that was covered before.