I disagree, an aftermarket ecu will always be far superior to a stock ecu, in both monitoring and performance metrics.
He was also talking about a piggyback which just "tricks" the ecu it doesn't replace it. Chris, on the other hand, an aftermarket ecu will almost always have a larger table to work off of when tuning so there are very few instances where a stock ecu will be better than an aftermarket one. In the case of the mirage though. If it's flashable I doubt people will exceed the needs that a stock ecu can handle especially if it's anywhere near the capabilities of an older evo ecu.