Another consideration is the 'local' weather,as many unhappy hours will be spent in the clubhouse just waiting/hoping for that front to pass through or the mist/fog to burn off !
From my limited knowledge of the two,Blackpool seems to have the better weather(sea level) along with more runways to choose from thus minising grounded time due to crosswinds.
Oh and one final point, it is very hard to get 'lost' around Blackpool due to being situated on the coast and having a bloody big mast in the form of Blackpool tower therefore making nav exercises considerably easier.