I have had mixed success using a property manager (or property management company). Give me your ideas on what you believe makes a good PM? What skills, personality traits, or tools are necessary to be successful?

First and foremost the ablility to collect rent, sometimes they have to be very diligent about this and do a sneak attack on Sunday:)
A very good PM will be able to fix the minor problems of a house and know quality companies to call when major things require fixing.

To me, what makes a good Property Manager is many fold:

1. Over communicate, over communicate, over communicate. Keeping an owner up to date on matters related to their investment is veyr important. Just making a phone call at least once a month to stay in touch will do wonders for the owners confidence in the PM.
2. They always know that they work for the property owner and not the tenant
3. They document everything that is a discussion, agreement that is related to monetary issues or related to the rental agreement. This is where PM's can get burned otherwise.
4. Yeah, getting things fixed is important. Just find a good maintenance person / crew depending on your size. A good one will take care of you and help your reputation.

Patrick
Rents2Riches.com

A property manager must be good at screening tenants. Selecting the wrong tenants can be very costly to a landlord. Simply doing a credit check and verifying rental history is not going to cut it.

This is what I do:

http://www.propertymanagementlasvegas.com/tenant-screening/

I personally manage my own properties, as I've always been nervous about having a PM take things over for me. It may be an easier decision for me to self-manage my properties as I only have 5 single-family homes that I rent. For those with 10+ homes/buildings...having a hardworking PM is more necessity than an option. I would expect a PM to manage my properties just like I do, but with the bar set this high, I know that I would have to pay out sizable chunk of my monthly rent for this service.