Severance offer, what should I ask for? - 3 weeks in

The company sent a severance agreement with a release of claims, and I am unsure what to do. I would rather hear the honest version than the polite one. There is a non-disparagement clause. Did anyone negotiate and succeed?

I asked for two more weeks and a neutral reference. They agreed to the reference and added a week.

An hour with an employment lawyer cost me a small fee and made me feel much safer about signing.