P, I think you have hit on the main issues with hiring your own PM.
"You would have to have a lot of rentals to make it worthwhile."
Yes some critical mass, that would vary depending on your PM. Could they be on call full-time and work several hours a month? You wouldn't need many rentals in this case. Do they need full-time work? That would take at least 40? doors to beat a real PM company.
"Most of the property management employee types I've seen don't seem to be too sharp. Smart motivated people can make more money doing something else."
Yes, unless they are young and the job market is poor and if it is a stepping stone.... Yes I agree, it is very hard to get someone as interested as you. Kind of like outsourcing your kids' education vs. doing it yourself.
"But maybe a college student who is studying business might be interested in some cash. You'd have to re-train someone new every couple of years as your manager graduated and moved away."
I think you are right on, but many positions have relatively high turnover, but if you can help build a career path you can extend the tenure.
"The trouble is that tenants are too much trouble unless you are getting paid a lot to deal with them, or else you are dealing with them because they are in your investments and you are going to make a lot of money."
As an investor you feel this way because of your bent, and you have other options. I mowed lawns for a living for 3 years after college. It was fine, just not a career. And I got a lot of good thinking, planning, and dreaming done while I was knocling out 40-50 ;lawns a week. Managing 40-50 rentals takes less work than 40-50 lawns. And builds wealth much faster.
"I manage my own becasue I can't find anybody else who will do a good job of it. I am good at what I do. I have good tenants, well repaired properties, and zero evictions. However, you couldn't pay me enough to deal with your tenants as well as my own. If I could invest in real estate and not deal with any tenants, not ever, I would be sooooo happy"
So far I am in a similar position as you, but I don't plan to be managing SFRs in a few years. Looking for scalable, quality help, hence this thread.
To deal less with tenants, why not look into commercial, or even better yet, NNN commercial properties?