I personally prefer my cats to use the tray, although this weather they do prefer to 'go' outside. I can keep checks on their poos, eg if they have diarrhoea, passing blood, etc. When we had Anna she suffered from recurrent bouts of cystitis and had it not been for her using the litter tray I may not have realised. Poor love, I would have hated to think she was suffering and I didn't know to do anything about it. If they use the litter tray it also saves them digging my garden. Just my opinion though!
