I'm sure it depends a lot, but for this situation, examples would help illustrate it better. 

@Heath Thomas Jr well that illustrates a small, but practical reason of why it is important to use an agent who knows what they are doing.

I thought it was funny and illustrated your point well.

Its a concept illustrating the compound effect when one strategically looks to enhance their network with 'connectors' aka people who's main intention is to be a resource for other high net worth individuals.

Recently sold comps are what you use.The Heloc will produce the same result.  80% of property value minus amount you still owe (80% x $600K = $480K - $477K = $3K).Therefore, currently your best option would be a LOC.As for your last question I think I already answered it.I agree that the refi may not be his best option for cash out re-finance purposes for the reasons illustrated, however it may still be worth while if he is able to get his rate and payments down significantly from the FHA rate he is currently paying.

When you go to sell years later, or should you want to illustrate your holdings to a 3rd party to get a loan perhaps, these numbers will be evident and show on a pro-forma.  

I say all this to illustrate that its nice to be proactive in adding to your team, but dont let not having a fully fleshed out team prohibit you from taking action!

Maybe you already appreciate the point, but hopefully that illustrates why the original question, while grammatically correct, is not really a logical one for most people to ask - "Better" CAP rates is a non-meaningful concept.

In Oregon for instance one city ban's nightly rentals  No Air BnB  you must have a permit to do this and they only give out a small hand full.This also illustrates clearly that when you buy rentals that are going to be section 8 your property is what it is and will never really go anywhere as for good bad or indifferent you are on the face lower the perception and reality of the area... so when you look at what's happened in the last 20 years were rental business has exploded into mom and pops you have whole sections of towns and cities that will go through and have gone through exactly what this article describes.The only time this reverses is if like this property its a big complex and the owners have the right to do this... or if its SFR in an area of a city that is regentrifing @Ben Leybovich  watching the move Thomas Crown Affair when I was on the stair master and the lead female ( Rene Russo) character was born and raised in Lima Ohio... how random is that.

Granted, the above is an exaggerated and unlikely scenario, but illustrates the simplicity and {one of the} limitations of CAP.