They seem to have a good business model and one of the owners is an investor himself which is definitely a plus, but they charge a leasing fee (to find and get a qualified tenant into the property) equal to 1 month of rent, which comes out to an additional 4%-8% on top of the monthly 10% maintenance/management fee depending on how long the tenant stays.

The second question is what criteria do you use for deciding when it is the right time to expand your model to look at other opportunities that you may not have considered previously? 

I had my fare share of financial modeling and asset management and can say I know how to analyze deals and asset manage very well.But, I was not too involved in the closing phases of the deals (lawyers, reports, debt placement, contract negotiations, parts of the DD...) so I lack knowledge in those parts, which I make up for in reading ton of materials and listening to podcasts.• After that I worked for three years as a management consultant at McKinsey where I sharpened my business acumen, problem-solving, storytelling, and presentation skills.

Doesn't sound like it will be a particularly hard model to copy, and when the word gets out you could find 10 houses on the same block under cutting your prices by 50% or more. 

The whole financial freedom through real estate movement/model has been created on the back of artificially low interest rates following the Global Financial Crisis and that model won't work anymore for most unless interest rates or real estate prices in the US drop dramatically and most economists think they won't and for good reason.

For the AC, I went with the GE Profile ClearView window AC unit, specifically the 8,300 BTU model which runs off of a standard 110v outlet, and is available on Amazon with Prime shipping.  

I think that he has a very good model. 

There is also alternate rent models such as STR, MTR, rent by room.  

Although the rent by the room model does come with more upfront work, and more tenants to manage.

@Robert Ellis yes we have a duplex model that we build in Lehigh Acres and Cape Coral.