How to find a reliable management company

[Scarlett Tao]

Landlords and professionals,

How could I find a reliable property management company/ leasing agent? My current one was recommended by my real estate agent. Seemed to be a good one until they started to work for me. Take forever to finish some repairs/update. Not good at leasing units. Their website/online review/office are Okay. 
But I don’t know if the next one would be the same. 

I have a multi family in downtown Seattle.