I voted for Elizabeth Warren yesterday. I've been a supporter of Klobuchar for as long as she was in the race and would have voted for her had she not withdrawn. So my choices yesterday were Bloomberg, Biden, and Warren. Sanders is both too old and too radical for me to consider, though I will vote for him if he becomes the Democratic nominee.
My bottomline was that anyone my age is too old for the job. I think I'm still pretty good mentally. My memory fails occasionally, more than it used to, but I can analyze and write pretty well. Assume that Bloomberg and Biden are equally capable. But I find it hard to imagine that either man would, if elected, be able to credibly plan to run for reelection. That's just an age too far. So they'd be a lame duck immediately. The record of our presidents during their second terms when they're lame ducks is not great.
The VP, whoever it is, would naturally want to run for president in 2024, which would likely mean she'd need to establish some distance from the president just to have their own identity. Meanwhile other Democratic politicians would be maneuvering to run as well. All that means big difficulties in getting the party to come together and support the President's proposals.
Applying the logic above leaves me with Warren as my choice. I'm not fond of some of her plans, but I like her brains and her passion, so she was an acceptable choice. When I voted, I realized it was a symbolic vote, since she had no chance to win delegates in VA. But that's life.