I got the buy out offer as well. I'm not taking it and here's why -
As a part timer for 7 years, drawing at full retirement age, I'll get $350 a month from the company administered pension plan.
Knowing how insufficient my Social Security income will be, having that $350 could well save me from utter destitution later on. At 63 years old now, IMO it's too late to roll any payoff into a better investment.
-AND- for many purposes and applications, one must show a verifiable monthly income. Places which require a verifiable monthly income will not usually consider savings or investments as income. They want to see guaranteed monthly annuities.
So that both the SS and the UPS pension will be counted together combined as guaranteed monthly income.
(You young kiddos just wait until you get older and try to rent an apartment or something. Even if you offer to pay a zillion dollars cash in advance, they won't take it. You need to prove sufficient monthly income.)