What are the bike routes around each like?
From a Travel perspective, very scenic. From a cycling perspective I would guess "challenging" but I have only walked and driven in the area and for me the cycling perspective is probably limited to either "challenging" or "impossible". Ronda is only ~20 miles inland but over 700m above sea level and as I recall the drive to it was near vertical in places.
Andalucian Cycling Experience hires bicycles in Ronda and its site mentions:
The Serrania de Ronda is a cyclists paradise with mile after mile of fabulous mountain bike trails and well surfaced asphalt roads too! This is one of our main playgrounds for riding (in fact we refer to it as ‘our office’). The diversity of the countryside allows us to ride through the Serrania de Ronda with families, leisure cyclists, mountain bikers and roadies but more importantly provide a route suitable to all the wide ranging requirements of these groups whilst on their cycling vacations.
I do know cycling is popular in the area and there is a choice of routes – over 500 km without traversing the same stretch in the same direction. I also know that given a choice of returning to Ronda or Girona it is Ronda I would select.
Stacks of cycle routes around Ronda are detailed here and Cycleronda has a map that is basically the 500 km I mentioned - six different routes ranging from 26 to 54kms, with five of these 'circular'.
Since your preference is for Ronda I suggest there is no need to sing the praises of Girona here – let your husband try and persuade you, if he is foolish enough to attempt to.