I have a 5.7 LS1 with a Current Performance ECU/harness. No big power adding mods have been made to the engine. I don't know a whole lot about tuning so I don't know how much of a difference a professional tune would make compared to the base tune the ECU came loaded with. Does anyone have any experience with this? Should I leave the base tune or would it be worth the $300+ to get it tuned?