Seems like 64 is the spot for me. My full retirement is 66 1/2. I’ve seen too many people put it off, start collecting and die not long after that. Another thing I factor in is advice from my nearly 90 year old neighbor. He tells me that you may think you need a lot of money when you’re in your 60s, but by the time you hit late 70s, you just don’t need much money, you don’t do as much.
I have a tendency to agree with this. I think for many reasonably healthy people, the 60's are going to be the most active decade, but each successive decade will slow down. Anecdotally, I would plan to do the majority of my remaining traveling in my 60's (just shy of 7 years away), and go strong until the middle of my 70's. We'll see what happens after that.
I'll have other income streams, and won't necessarily have to take my SS at early retirement age, but I can't see waiting until full retirement age, either.