I am a sitter myself, for the Dordrecht Cat Care Society, and I love cat sitting.
Most cats, even the shy ones, really take to me. If a cat is only interested in fresh food, I just clean the litter, wash the bowls and refill them, while talking to the lord or lady of the manor. But if a cat shows any kind of interest or affecttion, or seems lonely, I will stay for a while (sometimes quite a while), to talk to them and cuddle them.
I have several regulars, who recognise me the moment I come in, and will greet me like an old friend.
My own cats have several part-time slaves.Usually, one of my neighbours will take care of them, but my cleaning lady always kind of hopes they will be on holiday, too, so she can step in. She loves my cats to bits, and they graciously accept the adoration.
So I'd prefer a sitter any day.
The only time I took a cat to a cattery was when Tosca was injured and wearing a collar. She needed special attention, so she had to stay in a pen, anyway, and being a feral cat, no-one can handle her but us. So I took her to a cattery, the owner of which also resocialises stray and feral cats and kittens. She was the only person I knew I dared trust with Tosca.