No experience of Hamptons I'm afraid. Not sure why but maybe they did not have much property in the Bermondsey street bit of SE1 at the time (which is where I was looking).
Also wanted to add one more tip, which is to check their website for ease of search and adequate information. I remember doing this for lots of them and found ease of use and amount of info varied a lot. But perhaps even more important is that they list on websites like 'rightmove', the number one search tool for most looking for property in London these days I think. I always fancied myself as a bit of a 'Phil & Kirsty' (*not saying which one*), hence my unnatural interest in all things property wise ;-).
We found Caddington Blue after despairing of the experiences we had with other local high st agents. Caddington Blue have restored our faith in estate agents and we would recommend them in the strongest terms to anyone. They really are an outstanding and unique estate agency who give personal, intelligent and superior service and take pride in this rather than taking the money and running which our three previous agents had effectively done. We would never use nor recommend any other agent and feel extremely lucky to have found CB and discovered the quality side of estate agency. Jane & Guy Turner,doctor and teacher in SE1