Did this last year. Cheap flights with GO are a deciding factor with my marathon programme.
Conditions were perfect (ie. the weather, not my body).
Start is dramatic with fountains, grandiose Spanish buildings. Course flat give or take the odd bridge, I think. Organisation good.
Don't get too worn out the day before chasing around all the Gaudi treasures.
Don't worry that so many of our Catholic cousins cross themselves a lot before the start of a marathon. And enjoy a huge bowl of paela afterwards!
