In reply to Daniel James: I'd say if you can afford it, Its worth doing both.
Its what i'm currently doing, CWA as a first aim and the SPA as a slightly longer term goal. Admittedly I am climbing a lot at the moment, indoors and out. But the way i see it, as i'm working towards the qualifications, it means every climbing session is in at least a small way valuable not just for the climbing itself, which of course is fecking great, but also towards my quals and in terms of experience.
Even sessions i'm too shattered/injured to climb, just reading routes as my friends climb can be useful, plus you are in a way 'coaching' as you encourage your mates anyway! (as well as the belaying experience!) For example how many times have you or your mate managed something after the other shouted "Other foot/hand yer tw*t!" or something similar? Plus the on site experience is priceless.