Rounded edge quartzite coping stones on a free form pool.

Very nice - but we are going pre=cast concrete route so too late for us to copy your beautiful coping. We have to tell them the edging now!

I can't speak for pre-cast concrete, but we have a pool with natural stone coping which obviously can't have a rounded edge. It is free form, too, and the chiseled edge looks great, so I don't think the aesthetics of straight vs round should concern you. As for leaning your neck on it, I would say the amount of time people use the spa vs the amount of time people spend hanging out by the pool at the fire pit pales by comparison, and the way it will feel wouldn't be my first consideration but rather the way it will look.