My gauges are TIM because I like the look of them and they don't cost a fortune. On a gauge in a car, you aren't looking for absolute accuracy, what you are looking for is a sudden unexpected change. For such a change to not show on a gauge would mean they would have to be absolutely hopeless. I would certainly never use a dash gauge to set boost levels, but I know for certain my TIM gauge would tell me if it started overboosting.