I am in Idaho and have built a prosperous and rewarding business based on this exact concept.

In order to feel better I have started laying out the 4plex design concept.

I like the concept of keeping things simple.I would buy the property separately without your friend.It might sound fun doing a business with a friend but a business arrangement is almost like a marriage.One issue that I can see is the timing of sale - who gets to decide when to sell the propertyHow much time will each person spend?

there hasn't been a ton of discussion since it's a fairly newer concept let me know if you'd be interested in discussing further.

Even a basic grasp of those concepts will help you evaluate deals more effectively.

We put up signs suggesting opening the windows when using the fireplace for fresh air, but that whole concept scared the crap out of me.I found paper ashes and matches in the fireplaces when they had push-button start, so that also concerned me.I found what I think was melted marshmallow on the logs, so that concerned me.Long story short, I would go electric. 

The more disposable funds you have each day/week/month you have a quicker balance payoff and less total interest will be paid.This is the concept atleast but yes the above should have the built in assumptions and if they didnt give it to you then it might be a bit misleading.

Similar concept, as a way to sell a property off instead of 1031 exchange and minimize tax obligation. 

If you were in the market, would you jump at one of these homes or hold back until the concept proves itself?  

It is nice you know the software but the concepts are more important to know than the software, so you can read the financials to find what is wrong.