Unless they make collapsing cars or start teleporting people, the ability to have 1-car parking near center city will be worth its weight in gold.

Well worth it because the dump charges you by the weight of what you are dumping.

We figured it's a good card to hold onto; they have done NO upkeep on the property in the 6 years they've owned it, and our knowledge of the property's history could potentially be an advantage (although not really necessary.

Get a RE attorney to make sure you are protected in the contract and no matter what the seller says about the upkeep, do ALL inspections and do not give anything away because you think they like you and you like them.

But given the topography this one could only be 4 stories as weight was an issue with the steel pilings.

If a wood structure, then there is a wooden header behind the block and above the door that carries the weight of the building.

I have clients that love them because some big ticket maintenance items and upkeep are included in the cost and it makes it more passive.

I am debating whether to keep them or fill them in before renting to avoid upkeep and liability.

You need to weight all the pros and cons to decide if it worth for you.

Awesome post, I've been working on building a weighted score to find `hot spots` to invest: https://www.biggerpockets.com/forums/55/topics/813403-new-bp-member-buidling-a-model-for-analysis?