For large Multi family deals, it is common to have listing agent as dual agent. When I sold one of my large buildings, I felt my listing agent was pro-buyer. The buyers were some real estate investment firms each with more than 500 million in assets - guess listing agent was trying to develop long term 'relationship' with big clients, while I am a small fish. I escalated the issue and listing broker changed the agent and reduced my fees. I got better offers from other buyers (seems 1st listing agent did not present my deal to all potential buyers, he only presented to his 'select' list) once I changed the agent.
As seller, you don't want what happened to me where listing agent was limiting buyer pool to his 'select' clients.
If you are a buyer, you will be at disadvantage competing with large institutions no matter what due to cost structure. You don't want the dual agent create environment where you believe you are in a bidding war - against yourself.