In my experience most people think that the most important part of a deal is negotiating what they are buying/selling.
They quickly learn that this is the easiest and quickest part of the transaction.
It is not the Buyer's decision or the Seller's decision if this deal will actually proceed to completion.
It is the Landlord's.
He or she is the one that actually sets the terms for the deal - the Assignment of the Lease or the issuance of a new lease.
Just to make it more fun, they almost always charge an exorbitant amount for your "application".
$2000. To apply. And it's non refundable.
Some of the larger landlords will also charge a $4-5000 assignment fee.
For what? "Paperwork fees" aka gas money for the Chris-Craft.
Both parties should expect that the process of waiting for the Lord to approve the deal will usually take 3-6 weeks, and no amount of emailing/calling/complaining tends to speed this up.
Take note and plan accordingly!