I mean, if it was Sanders v Biden, I'd take Sanders all day, with any VP, even if doctors and psychics agreed that Bernie would not serve more than 2 years.

But that doesn't require much research.
Sanders has a vision for America.
Biden doesn't.

Trump has vision all day, or can at least talk like he does. Biden either doesn't have it or can't convey it.
That's why Biden is a shit choice to go up against Trump, IMO.