I get that Dinan is very skilled and probably builds some really amazing race products but some of their other stuff is just ridiculous. Why bother with a tune that gives no perceptable difference in driving? Been there with a Dinan tune. For 1k nonetheless. Or an intake elbow for 1k that does nothing. Or bored throttle bodies which any car I have seen dynoed with them (non-m3's) lost power.
Why even bother with a tune if you are going to have customers not get anything out of it. Tuning is not rocket science. Building engines is a different story and if I needed a one-off custom race engine than yes I would go to Dinan but aside from that its just not at all worth it