@Shawn Tuma definitely depends on the number of units to a certain degree but PM software is great for a number of reasons, some of which you stated and others you didn't.1.

Coming from a software engineer background myself, I have peers and friends around me that are starting to get into RE (they are afraid of the stock market) and you know how the market is in Bay Area.

We just started using that software this year and we love it.

We use accounting software that codes the income and expenses to the property (called a class) so we can run P&L;s on each property with ease.Your accountant and bookkeeper will also thank you later for keeping it simple and avoid significant accounting costs. 

@Yixin Huang we use a property management software which keeps the communication centralized and updates them on status. 

What kind of software do you use if you don't like to drive for dollars  ?

Based on my experience, you either pay some more but get a high-quality service, or you have really raw but cheap software.

My understanding of the current text messaging compliance is that it's OK to send unsolicited texts as long as you don't use some kind of software/automated technology.

Not sure how good is that business as my son had made that software in couple weeks to sell School/college tickets online. 

things missing in your list (everyone manages differently, so take it with a grain of salt)Vacancy rateTurn overbad debt legal fees (evictions as needed)accounting fees for professional tax prepmaintenanceProperty TaxesSales Tax on PM fees (In NM, this is charged, not sure about where you are)Reserves for replacement CAPEX - furnace, water heaters, ac, roof, parking lot, etc.Admin, software, advertising, etc.Cost segregation study for accelerated depreciation captureAs for your loan.