While I think about getting into the VEI group buy, I figure now's a good time to ask what's better if I plan to tune the car later. VEI has their wideband display which matches their other gauges and uses a PLX or Innovate controller (and others it seems). Or they have an EGT as well. For tuning, a wideband seems somewhat direct measure, but I keep seeing people say that an EGT is better for tuning. Why is this? And how exactly is an EGT used for tuning?