I work for a 4 yr university, and this is all correct with a few minor updates:
Its now up to the rule of 84. I'm grandfathered into the rule of 80 however. And it used to be the avg of three highest salaries, now its avg of five highest.
What fucks a lot of people on defined benefit plans is that if they also are eligible to collect SS, their SS payment is reduced because of their retirement pay. I'm not sure how that works, but it can screw you pretty good if you aren't aware of it when you are working.
edit to add: You can select various payout schemes: as mentioned above you can reduce your payout and your surviving spouse continues to get your pension after you die. You can also reduce your payout by alot more, and a surviving dependent of your choice, but only one, continues to get your pension until they die.
I think you also (I need to check on this) can continue on your employers insurance (mine is actually not bad), without their contribution of course, if you retire before the age of medicare.