"mini mortgage" in partner structure?

[Brett Mach]

Reading Avery Carl's recent STR book and came across a partnership structure I'd like to hear more about in ch. 3, if anyone has details or experience. It could be for any strategy--not just STR...

There's a money partner and sweat-equity partner (I'd say "managing" partner in LLC lingo): the money partner initially collects all profits in a scheme where the sweat-equity partner works off his or her half of the initial downpayment in what Carl calls a "mini-mortgage." Her term might be a little confusing, but it's functional enough (coin something better, anyone?). Once the sweat-equity pays off their half, they split cash-flow, profits, 50/50 like normal.

I have mostly seen much simpler info where both are equity partners from the jump--maybe 40/60, 50/50, or whatever they think is fair in terms of value brought to the partnership. Is this structure as common as she makes it out to be? 

At a glance, it skews as a better deal for the money partner, because once the sweat-equity has "paid off" their half, they are (likely) continuing some level of management responsibilities that the money partner isn't worried about. Perhaps it's fair, just because the money-partner made the deal happen in the first place, or there's some other factor that I'm missing.

I know there are a zillion posts about partnership structure and the details...yes, I know "whatever you and your partner decide between you" is true. But as I create a multi-member LLC, I'm wondering if I should use (or feel some obligation to consider) this "mini-mortgage" strategy as the sweat equity partner.

Thanks for your thoughts!