@Joseph Blankenship Partnership fights rarely start at closing. They start the first time money is short. Three things worth putting in writing with actual numbers: how big reserves are (something like 3-6 months of expenses, or a set amount per unit), what happens if a partner can't fund a capital call (do they get diluted, and at what rate), and how a buyout is priced (appraisal, a set cap rate on trailing NOI, or a formula).
If you can't agree on those on paper when everyone's friendly, you won't agree later when the roof fails.
I'd want everything clearly spelled out before putting money into a partnership, especially who is responsible for what and what happens if things don't go as planned. The exit is a big one too. It's easy to agree when everyone is excited about a new deal, but people can have very different circumstances a few years later. I'd want to know ahead of time what happens if one partner wants out. A good partnership agreement can save a lot of hard feelings later.