They are far more common now and harder to find models without but:1) these add cost to the purchase price2) they don't bring a lot of value3) they can leak or detach and damage the propertyI own around 50 doors and I cap off the line at the wall or in the basement with a valve and a cap so the potential for leaks is 0.00001% :-) 

This will impact your costs and time commitment.Risk Tolerance: How much risk are you comfortable with?

You will have enough for a small downpayment on each option, depending on the area chosen in each case, and you won't have much of a cushion after closing costs. 

If the cost to get it running again is not too much (< $5k?)

Clearly there's a lot more ROI and work for a BRRRR.After finishing David Greene's BRRRR book and combing the forums, my impression is it'll come down to building the right team and doing our due diligence on finding and analyzing deals, estimated ARV, rehab costs, and rent /demand for an area with the most conservative estimates. 

Understand the fees involved and calculate the total cost for an entire year of management so you can compare the different managers.

And, when there is a vacancy, can the remaining units provide enough cash flow to cover all costs?

Simultaneous to that, negotiate price reductions to the greatest extent possible because of this extra cost you are incurring. 

Here's a fundamental explanation to get your juices flowing:Assume a house costs $200,000 and rents for $1,500.

Once the above skills and tools are acquired, understanding the sequential process of the development along its timelines and costs needs to be correctly implemented.