Yes I think the spa is worth the extra money. It isn't too much more & makes for a very smooth ride. I never know quite how to describe the feeling when you hit a bump, a bounce I guess. The "upright" position was just different.
I am liking it now that I have ridden it more.

It does sound like your body type would be more comfortable on WSD my body type is the opposite. Short legs with long torso. I did switch to a shorter stem & narrower handlebars.