First, the downside of a Biden presidency.
What downside? Are you crazy? Our current president is on track to blast nearly three trillion dollars into confetti this year alone! After that it's just a matter of degree as in, would you rather be burned alive at 700 degrees or 715 degrees? There is no downside.
No onto the good parts. A Biden presidency would be hilaaaaaarious! Every day you would wake up and rush out to get your morning newspaper (I'd resubscribe just for this reason alone) to see what idiotic thing he had said in the previous day. Imagine the press conferences! They'd be vocalized M C Esher drawings! And think of what his press secretary would have to explain on an almost hourly basis! C-SPAN would become the #1 comedy network. Heck, I'd TiVo the thing just so I didn't miss a bit of the fun.
Really now, what would you rather have? A Bourbon Dauphin who has himself confused with Zeus or a Jerry Lewis clone in the White House?