It didn't work that way for us. My sister and I rent out our parents house in Notting Hill, West London, ever since my dad died back in 2000. The house became vacant again at the end of February. We decided to completely refurbish it, then go for another rental, rather than sell it in the current depressed market.
We finished the renovations on March 22. We saw three EA's on March 23 and placed the house with all of them. Two sets of renters wanted the house, so a bidding war started, and the house went for the asking price. We had pitched the asking price high, expecting to be knocked down, so we were very pleased when we actually got a higher price than we expected, with the tenants signing a contract for a year with two months rent as a deposit.
I'm sure West London is not typical of the rest of the UK, but our experience as landlords in a 'renters market' was certainly a good one.