very true, that is why i said to make sure you get a good tuner, the place where i got my car redone, used a dyno dynamics and did full sweep on the loads, both load based tuning at cruise/part throttle, and wide open, there is definitly a difference between having the car dynod on the mustang dyno and now on the dyno dynamics dyno ,car runs much better...
and you bring up a good point, if your car is a daily river the yeah i would just go in with egt and afr and do changes that way, but if its not a daily and more of a powerhouse/trackcar, then i would defiitly go to the shop have it all configured and tuned to the max efficency, thats exactly why i brought mine to the shop.