We recently bought our flat thruogh Central and can honestly say they were no where near as awful as the comments here suggest.
James Bostock, who was the agent for the property, was friendly, helpful and accommodating, showing us around several properties including some new ones on the market he thought would suit us. Not once did he try to bully us or persuade us on a place we didn't like. He took our requirements and preferences into account and used them to narrow down our search.
Once we put an offer in on the property the dealings with the agency continued to be fine. There were one or two occasions where telephone calls were not replied to, but we just rang again. These guys are busy so give them a bit of leeway!
The only point where I was not impressed was when we made an appointment to view the property and the agent (not James) hadn't logged it properly and therefore didn't turn up, but after a phone call he came within an hour.
Overall it was a good experience, and I would use them again.