Biden will be Biden with a few gaffes maybe, but he is generally well informed and can speak on stats, policies and specific steps to accomplish said policy.
When it comes to Trump, i always think "A goal without a plan is just wishful thinking." When Trump says something is going to be "bigger", "better", "beautiful" or that "you're going to love it", I'd like the moderator to pin him down and ask how and get an answer other than he will negotiate, they're working on it and will release it shortly, or so and so will do it for HIM but no one else. Or rthat he has a plan but he's not going to tell the rest of us what it is.
He generally cannot cite policy or concrete steps because he is implementing plans other people have put in place. It's also why he is not loyal to one position such as abortion or immigration, he has no skin in the game, he is implementing someone else's policy. He's just the face of it. He licenses his presidency and name on other people's policy like he does his name on other people's buildings. His position will always change to whatever is most beneficial to him, regardlessbof promises made, but he can never tell you how something will get done.