I think we will be surprised by how many 55-60 year olds take it.

It appeals to anyone who has made their retirement goal, has a military pension, an SO with a good income, and/or a successful side business. Younger than 55s have the issue of health care as you can only make it last ten years (assuming enough sick time).

It's also attractive to older, but junior FOs who are could believe they are in danger of furlough (I don't think we will furlough but others have a varying assessments). It's an almost safe bet to take $100k/yr over five years and go look for other work than take a chance on a furlough.