Well to keep it fairly short...
Most sports anime have made it big time due to its awesome story pacing,adrenaline filled matches and last but not the least a backstory for most of the imp character.
Ahiru no sora is fairy good but looses out in the pacing of the series . The charcter development is also fine but the plot is very slow (51 episodes to restart their club) But the anime has a lot of potential for the future .So this is one to watch ou for later
Another issue facing the anime was the constant clashes between the manga creator and production house which made a bad name out of itsleft. Above average but hope to see it improve in s2(Heard rumours s2 will be released )