I have done this a few times myself and have a few basic recommendations:1) Make sure the seller owns the property free and clear and that it's very clear to both parties whether the arrangement involves a deed of trust or contract for deed2) If a balloon payment is involved, be sure to assess your ability to refinance and make that balloon payment in the future- optional extensions can help manage this risk3) Understand the tax implications if the interest rate is notably above or below market rates4) Get title insurance! 

To a future reader who comes across this same issue, what did I end up doing?

My wife and I own and manage 5 units as MTRs, and while it is certainly doable to manually update calendars across all the platforms (don't get me started on the deficiencies of iCal), we are looking to build a good foundations for future scaling as things are going well. 

I build tiny cabins near Houston and do STRs but I am in the process of building a tiny home LTR community in the future.

It's the spread between the purchase, ARV, and future cash-flow (lunch money). 

By asking us to fund repairs and then recoup them from future rents.

While the interest rate might be higher, you eliminate the risk of needing to refinance or sell later, making it a safer option if your goal is to hold the property long-term without any financial uncertainty.If maximizing cash flow now is a priority and you're comfortable managing the future refinancing risk, owner financing with a balloon could be the better choice.

This weekend I was lucky enough to attend an MFIN - Multi Family Investor Network - conference here in Colorado and see BiggerPockets CEO @Scott Trench share the stage with @Ben Suttles and @Feras Moussa talking about the future of real estate investing, plus a number of other keynote presentations and informative breakout sessions.

The only way to tell is by a careful review of your current situation and your expectations of your future situation.

It's hard for me to know how much cap ex and repairs will be in the future as the price of those things goes up.