If you use an application designed for landlords you'll get some critical features that you won't find in a general accounting platform like Quickbooks or Excel. 

I'd say the critical component to securing a worthwhile multi family investment (and any real estate for that matter) is timing.

It's critical to choose a strategy that works for him.

Location could be critical to your goals.

Constructive criticism, if received, is always a good thing. 

Something that doesnt change the critical path to getting the project done.  

After reading your thought-provoking post and responses, I felt compelled to contribute some additional insights to the discussion.While the existing advice holds merit, I want to underscore the critical importance of strategic location selection in real estate investments.

When levered, I find it critical to be able to enter into an investment cash flow positive and underwrite it conservatively.

I haven't done any research into the Fed-ex Freight/Custom Critical routes because it's hard enough recruiting prospects with squeaky clean records that the company would qualify with a standard C class License.

That allowed me to jump into neighborhoods slightly ahead of critical mass, which significantly helped to lock in my success.