PCP's work for people that are happy paying £x each month to have a car in warranty to drive around in. They are seen as affordable way of getting into a car, with little up front outlay, however because you deffer a large amount of money to the end of the deal, it is overall more expensive as you take longer to pay the money back.
I wouldn't want to put down a deposit, pay lots of thousands to pounds for three years, then be faced with the decision of A- having to find a substantial amount of cash, which may mean more finance, B - hand the car back and have nothing to show for the last three years, or C- be forced into using what equity you have in the car as a deposit to start all over again with another deal on another car.
People will come on here and justify that buying a new car in this way can be cost effective over buying a used one with cash, but to me, I prefer to not be beholden to anyone. If my income goes to pot, I've not got to worry about finding the monthlies. If it gets even worse than that, I've got something that I own to sell.