What lien position are you in vs the 'other guys' ?    IE what if the rent/lease isn't paid, what are your options?
I would want the rent in the first lien position, but I bet they are reluctant to go that far.
Make sure you have an escalator in the contract to account for inflation.    
Will they clean up after themselves after the contract expires, if not, what are your options?   I would want some sort of bond, escrow account to guard against them just walking away.    Contract payments start when they sign the contract, not when construction is done.L
Lots of things to consider.
Karl