For a homeowner
Every year they charge more and offer less. Now, you are forced to use their online payment system or have a terrible ranking. We use a management company and can't use their payment system, which means a much lower ranking. My experiences with their customer service have been brutal as well.
For a customer
If you use the online payment through vrbo and have a problem, vrbo customer service is horrific. You have very little recourse and will just be frustrated and probably lose $$.
All our reservations run through a great management company with fantastic customer service. In 8 years, there have been no customer service problems. Booking our place through them is a much safer and overall much better experience.
If you have a problem after arrival (water leak, heater failure, phone doesn't work, internet doesn't work, etc.), who will you call? VRBO? Good luck getting them to help. The owner? Maybe helpful but also could live far far away and make things much harder and time consuming to get fixed, or not get fixed. If there were a problem in our place, you have 24 hr access to help and very fast turnaround.