2.4 VVT Tuning...overlapping maps from HHR/Solstice/Cobalt?

While i understand exactly how VVT and cam timing works, I have never actually had any hands on experiencing with tuning VVT precisely. The thought occurred to me a while back that overlapping ignition spark tables using the same motor but different models of car's to fill in gaps in low RPM areas that were either difficult to tune, or really just helped improve cruising throttle response. This worked surprisingly well using a combination of the HHR and solstice 2.4 stock tunes of the same model year and engine type on the cobalt. As shown below... (these are compare file images, the numbers represent how much more vs the stock table)

http://www.hostthenpost.org/uploads/...b5e5477bd6.png

The rest is all a matter of datalogging and recording and watching for KR. VVT on the otherhand is an entirely different story, as you have the relationship between the intake and exhaust cam to be concerned with. If I overlap the 3 tables using the maximums for each (intake and exhaust high baro tables) I come up with the following compared directly against my stock cobalt VVT tables.

http://www.hostthenpost.org/uploads/...67359fa6fb.png
http://www.hostthenpost.org/uploads/...8333274868.png

Now i can test both of these against my stock tables at the track to see if there are results, but I can never truely know if im hurting or helping the airflow in and out of the engine by making these changes, and if these changes do wind up yielding crappy results, what if any changes should i be making to the VVT tables for better performance? Rumor has it around these forums that people have seen gains of up to .5 seconds depending on how aggressively they tuned the VVT.