We have pigs on slats and straw, we get less fighting, tailbiting, illness and ultimately death in the slatted sheds than we do in the straw pens. The slatted finrone flat decks we have for weaners almost completely eliminated our antibiotic use from day 1 unlike when we had them in straw. I think you'll find the research shows this to be a common theme in the argument for and against. With the reduction of antibiotic use at the forefront of peoples concerns when it comes to resistance to them. It's always going to be better not to be walking about or lying in your own sh1t! I suppose they do 'look' better on straw but it's all subjective. In a nice clean heated slatted shed pigs look every bit as happy as the ones in straw, they're just not snuggled up in straw because they don't need to be.