If you're trying to buy-and-hold you probably want to focus on your thoughts on the longevity of the market instead of 10% vs. 8% cash-on-cash returns 🤷🏻‍♂️

I don’t know that anyone could say it would be forever, but should be good for a few decades.I would hope local contractors would know enough about the soil your property is on to tell you the longevity of this type of solution for your property.

Also, see their client list and the longevity of those clients.

Very efficient.Chances are the older system has substantial duct loss and should be tested.Mini splits have their place but cold air is heavier and drops so the bottom floor doesn't make sense.Electric motors do not raise in load consumption as they age, it's the mechanical work done that raises load, typically deferred maintenance on belts, shives and pulleys.I'd disqualify HVAC companies by asking; Are you proficient in the new Manual J,S & D standards (that will be required in the industry moving forward)These companies will understand laminar flow, stratification and static airflow imbalances that have a great effect on efficiency, operation and longevity of a conditioning system.Get 3 estimates, compare scope & make sure its permitted.

Does not matter what you love the gaol of a rental is low maintenance, low cost, longevity.

I do have concerns about the longevity considering the population decline. 

It is not a product warranty nor any suggestion of longevity. 

They won't all be great but follow that model that you have created.I like RE because of it's safety and longevity.

I personally buy in markets where that is higher and I also do pretty nice updates after purchase to try to “bullet proof” the home for longevity as much as possible - so I think that could be why I haven’t noticed anything that feels “above average” in terms of maint/cap ex.I DO think there are many properties in the area that if bought would have above average maint/capex because of the condition of the property and quality of tenant.

Bite the bullet, find a reasonable Roofer there in your area (not cheap, not expensive) but has a record of LONGEVITY there... and replace the roof!