I used one too. It was in Merseyside but I live in the south. Once I'd been given the name of the company (they were recommended by a third party conveyancing site), I looked them up and did some of my own research to find out more about them (ring tourist info, Citizens Advice, local police). If the company have a bad reputation you're bound to end up speaking to someone who has local knowledge and knows this. Anyway, I saved an absolute fortune. I sold and bought a property for peanuts compared to what a local firm would have charged. Having said that, I was buying a new build and didn't require surveys etc. Not sure I would take the risk if I was buying an older property that could throw up some problems!
I also work with someone who has just sold his property. When ringing local solicitors to ask how much their fee would be, he was told it depended on how much he was selling his house for! What a cheek. Are they saying that if you sell your house for �300,000, they have more work to do than if you sell it for �200,000?