If I wasn't a chef and had to choose which one of those recipes to cook, I'd go for David Cameron's one, as sausage and pasta is quite authentic Tuscan food. It's gutsy and hearty, and you could do it at a dinner party or elsewhere.
Gordon Brown's one is a bit too cordon-bleu cookery school for me, and it's not something that I'd cook. It's a typical dinner party dish I suppose, but wrapping things up in filo pastry is a bit old hat, really.
It's interesting when you think that both of them went for Italian dishes, but perhaps they have Italian connections, I'm not sure. It would have been interesting to guess which of them cooked each recipe, but both of them are good hearty dishes.