I have a used throttle body plate removed from a Volvo 960. People use these plates on the 850 Volvo NA cars to get rid of the plate with the plastic wedge on it. People report some throttle response gains when replacing that plate with this one.
Other people have used it in conjunction with replacing the intake manifold and throttle body on their turbo 850 cars to improve throttle response especially when tuning their 850, S70, V70 turbo cars. Upgrading from the turbo intake to the NA intake is believed to increase the intake air which improves throttle response and boost performance.
I once installed this plate in conjunction with the intake manifold and throttle body on a tuned S70 T5. My experience was that it made the car feel better throttle response. It was like driving a car with an ETM vs older throttle cable car.