Should I Seek a New Property Manager for North Phoenix SFRs

[Bill Alpert]

I've been working with the same small company for a few years now, and though there hasn't been a flagrant problem, I'm feeling like the owner has a marginal attitude and is frequently on the edge of being mouthy with me. At times it seems like he represents the tenant's interest more than mine. His repair and maintenance vendors have really flopped a few times, and that's cost me money. On top of that, he adds 10% to all the vendor invoices in addition to his regular management fee, which isn't low. 
So, at what point would you start looking for someone else?
If you have a solid experience with a company in Phoenix/North Phoenix, I'd love to hear about it. It's for a couple of SFRs.