I was think of adding some timing between 0-2000 and 2000-4000. There is no thing wrong with the car, but I was thinking that this make give it better low to mid range torque.
for what its worth, i would use a dyno to see if you are actually gaining power. much better than the SOTP meter. the drawback to this is that it is expensive.
I can tell you from my dyno tune this week, some cars don't like timing as much as others. With the "normal" timing settings on Brenspeed's 93 octane tune, my car ran very well but occasionally would have spikes in the upper rpm range while on the dyno; it was the knock sensors pulling timing out. Brent retarded the timing slightly and the spikes went away, and I gained 2 peak horse.
Since I always run 93 premium, I doubt that actual octane was a problem compared to other people. Maybe the cams weren't dead-on from the factory.