I have dealt through Marc Johnson on purchase of a flat for letting, management of the property and recently the sale of a flat.
On Purchase he was very honest with is opinions and represented me in an exceptionally professional way and concluded the negotiations quickly and kept me informed at all stages.
On Management he found reliable tenants who left the property undamaged and clean - They also paid in full and on time!
On Sale of a property he was a cross between efficient and incredible. We agreed a sale price and an expected price and he exceeded the latter. The purchaser was outside the country and he ensured I was kept updated even when there were money transfer problems from abroad. When problems arose he stepped in an brought the sale to a satisfactory conclusion.
If you want an estate agent who returns calls, finds a buyer who commits immediately and is unusually honest in his dealing with you, then talk to Marc.