5 Speed Gear ratio advice?

Thank you all for that technical class. It was perfectly timed as I was about to post a very similar question. I’m standing in line for a 855 5 speed. Before that I was looking at a 3:55 gear, but with an extra gear I can go lower, so I want to make a very informed decision - this thread will allow for that. That’s not to say my head wasn’t spinning a time or two...