We have one as a rental and have long term tenants there who are great and we have good communication in both directions.

On the other side, the bigger companies have more experience and their numbers tend to be more accurate (not always)... as they are big companies "their costumer service" and communication is better but at the same time they "have more mouths to feed" if we need to be honest so can get a bunch of ok or good deals but I kinda doubt they will be great (just my personal candid opinion).

It also allows you to manage paperwork and document communications with Tenants. 

Your going to the London School of Economics, your not some punk day dreaming from Mom's basement working PT at McD's who's best achievement was the dugout ya made in metals shop and got your first -B of your life wondering how to get Grant Cardone "rich" with you $85 of deployable savings...... 

So, communication and assignment issues, as well as not being able to explain the maintenance issues and the required work.3) Proper documentation and quality of work issues.

However, we are taking over from a PM to self-manage and are inheriting the current setup.Our biggest concern is that this first communication from the tenant was a sob story asking for $500 back/off rent.

They are also very unresponsive, you'll get a lot of upfront communication while you're signing up for things and then they disappear. 

(many contractors are going to bite off more than they can chew and communication will be key). 

Yeah, under any other circumstances, I'd suspect that, but I'm certain based on past communication that they are simply no longer responding.

A prudent investor doesn't seek quick riches through shortcuts.