One thing to consider is that you're basically going in to business with whoever you sell to on a contract. What is their cash flow and reserves?
If they don't make their payments to you, then you need to take action.
If they trash the house and you take possession, you get to deal with the mess.
That being said, I've known multiple people who have sold on a contract successfully, sometimes a five year with a balloon payment (meaning the balance is due in full after five years of payments, often useful for buying a fixer then re-financing once it's loan-able), sometimes longer, like twenty years.
Some people would rather have twenty years of steady income rather than one big cap gains inducing tax hit.
I was trying to negotiate a contract sale on a house my business partners and I built last year. The buyer wanted a lower rate so we settled on 5%, five year ballon based on a thirty year amortization,and a three year minimum term before a re-fi was possible by the buyer, but my partners were skittish, for the reasons I led with. Plus, we all preferred to be cashed out now rather than waiting five years.
I was attracted to the three years of interest (approx $130,000).
Also, the potential buyers were hard bargainers,and one of the partners got a little offended and didn't want to deal with them.
It ended well, we took it off the market and put it back on this spring and it sold with conventional financing, and everyone is happy.