I endured the worst experience by (regrettably) choosing Cairds in Epsom to help me through the process of renting for the first time - never again.
Aside from being pushy, disrespectful and incompetent at the start of the process, they falsely accused me as the reason for their actions towards the end.
After a lengthy process of Cairds employees accusing me of fraud and attempting to take my whole deposit and an extra months' rent from me, an independent adjudicator confirmed the fact that they were wrong and I was right. Consequently, I got my money back from these people.
All I can say is - get absolutely everything in writing, and be extremely cautious, especially if you're new to dealing with estate agents like I was.
n.b Their spelling is atrocious. All correspondence arrived with a different spelling of my name, every time. Still haven't decided whether this was pure incompetency or pure disrespect. Either way, that in itself proves what kind of establishment they are.