Four years ago we chose agent B because my daughter said that, when selling her house, she'd first tried agent A, who didn't manage to sell it, and after she'd switched to agent B she found they provided feedback about what viewers had said, whereas agent A hadn't.
Agent B had about six offices in the area, while agent A had only one. With the internet and sites like Rightmove that shouldn't make much difference. The managing director of agent B talked fluently and at length about how many of the homes they handled got sold without even going on the market, because they offered them to waiting buyers.
It didn't work out that way. Their representatives who showed people round made little effort to point out the plus features of the house; we could have done that much better, but they didn't want us to. After a few weeks they came to see and suggested that we should "review" the asking price. Their attempts to explain why they'd recommended the initial price were pathetic.
We took it off the market. Then someone who had been shown round by Agent B offered to buy it, and eventually did so (the delay mainly attributable to an incompetent solicitor, but that could form another thread). Because the agent had originally introduced the buyer to the property they could have argued that they were entitled to their commission, but they never did so, and we haven't reminded them.
Having other offices in the area, agent B reckoned they could easily find the sort of house we'd like to move to, but their suggestions were almost always wide of the mark. I still get emails from them telling me about new properties which match our requirements, but they hardly ever do.
