Same question:
I'm thinking about a tune also. It runs and sounds great, but would like to squeeze a bit more out of the Zed if possibly. This is what I have and don't plan on any other mods:
Mine is an '09 7AT and we only have 91 at the pump:
Stillen Gen 3 intakes
Nismo H & Midpipes
Top Speed Axle Back exhaust
24 row Oil Cooler (not sure if that matters)
Thoughts on worth it and what types of gains?
^