I am a landlord and have used Briscombe Nutter for full management of one of my rental properties. They are truly awful - do not give these people any of your hard earned cash!
Once a tenant has been found, they do not do any regular follows up to monitor any issues in the property, and on one occasion took over two weeks to arrange an urgent repair. They take a 10% monthly fee straight from the rent for doing NOTHING.
Take my advice, avoid them at all costs.
What agent could do to change your mind?
The agent needs to provide the service that they advertise, it's as simple as that.