I prefer Claude because I feel like he "thinks" with me. I feel like he's more of a co-pilot; sometimes he suggests ways to do things differently or gives me ideas I hadn't even thought of (usually not fully formed ideas, but they give me the impetus to refine them later). In comparison, with the chat, I feel like he does what I tell him to do (very well), but I don't feel like he's discussing ideas with me. And Claude's writing also seems more human to me.