It's a personal thing, related to your flexibility, strength, leg length and a number of other factors. I have been using 180s for more than 30 years. I ordered a new bike in 2002 and special-ordered 180 Dura-Ace cranks for it. For most people, those cranks are too long. I came from a time-trialling tradition and longer cranks enabled me to turn bigger gears. I don't like the feel of shorter cranks. If I were more of a "spinner", I would definitely want shorter cranks. In fact, my circa-1970 track bike had shorter cranks. They were advantageous for sprinting and fast turnover.
If you feel you have to step over a hill at the high point of a pedal stroke, you definitely want to go with shorter cranks. I've coached senior athletes in several other sports. I always advise the athlete to listen to his or her body. Do what works for you, regardless of other people's experiences.
Van