Just FYI, if you're interested in "secret" mode on tuner (must have Android App), try:
"If you tap down from the settings screen, you will see an auto-connect option that is greyed out. There is a check-box to the right of that. You have to tap that check box 20 times. You may want to try regular race mode before accessing the max mode."
If you read older threads about this tuner, I was in contact with the lead engineer at Dinan (Dinan merged with another company out of Alabama) and he gave me some good advice.
-- I can only go by Dinan's test results with using the same piggyback--but, yeah, of course the company who designed it who is also running the tests is not always the most reliable. I couldn't find an independent test run on it outside of Dinan, though. It'd be interested in other piggyback scientific tests done by independent companies on either a Dinan or other company's piggyback. Can you send some links that show where other Piggybacks made performance worse with the scientific results from independent sources?
Dinan, btw, has an open offer to anyone here to come to either their CA or AL facility to test out their piggyback on a QX30 since they've only done the tests on the Mercedes GLA for this piggyback. Let me know, and I can pass on their engineer's contact info.