As a buyer you don't have a lot of choice other than to use the agent that is selling the house you want. I've had the misfortune for this to be Cubitt and West twice now, although its the Arundel branch that draws most of my ire.
From the point you put an offer in you get the hard sell to use their mortgage broker and go over all your finances.
During the negotiation process we were not well informed. Several times they couldn't even be bothered to call us back about offers we had made. I waited a week once to hear back about an offer. You speak to a different person each time, none of them know or care anything about you.
When the offer on our doomed purchase was accepted it just got worse and worse. Things we'd been told about the property were manifestly untrue when plans and searches came back. Getting a call back for anything took days.
When things started to go really wrong it just became farcical as stories changed by the hour and contradictions abounded. None of them could remember what their most recent version of events was and finally at crisis point being promised an imminent call back, nothing for 24 hours. At that point I'd had enough.
I am not sure whether the vendor was as two faced, duplicitous and downright dishonest as they appeared to be through the medium of C & W but I do know that if not, their agent did them no favours whatsoever, and ended up costing them many thousands of pounds. It was such a relief when we pulled out and realised we would not have to have anything more to do with any of them.
Fortunately we went through a professional local agent for our next purchase and the difference was like a night and day.
I would never use Cubitt and West to sell through and if I saw a house that they were marketing it would put me off seeing it.