|Member kickerzx has made some very good posts on this topic.
Often finding issues with a setup is a case of 'you don't know what you don't know'.
When I switched from Nistune to the Link ecu, I was shocked (but not surprised) of the rpm trace. This was the data I needed to see to push me to finally going with a proper trigger setup.
This was at the 600rwhp range with Nistune, on pump fuel. My tuner said the he was having issues with random detonation, and he had to run alot less timing than expected to avoid this. Knowing what I do now, I attribute this to timing scatter.