Such plans are purely a way to diversify your tax-sheltered retirement savings into non-conventional assets such as real estate, private mortgages, Bitcoin, etc. 

Beyond that, obviously you'll want to more deeply dig into the expenses, taxes, condition, etc, but based purely on the ration of rents to purchase price, it sounds like a deal worth looking further into.  

Sounds like you have set it up as a purely pass through entity.You'll want to make sure that it is setup properly if you are using it in a self-directed 401K.

This is purely opinion, and I probably shouldn't even venture an opinion on this...but first, you are assuming the lender will forgive the deficiency, as opposed to pursuing you for it.

  :)But, as with much rhetoric, it is purely my opinion, and is therefore not worth much.  

Purely from the opinion standpoint of a buyer looking to live in the place (which is the type of buyer I'm assuming you have coming through), the no central air, let alone no a/c, in the north east is a big turnoff.

I'm still awaiting their response.I'm going to sell the building, not purely because of the recent problems but I was already planning to as I need the money for other projects.

A purely cash flow place in a lower end market that doesn't appreciate could be losing money even at positive cash flow.I would part ways with you on the 1M mark but only in that its the satellite towns of such cities that can have winners.

Outside of pure real estate books, you may want to consider the following business books as well:Warren Buffett's annual letters, especially those after 1977. 

There is only one source for lists that is reliable because every other list I've seen is a pure waste of time and money.