Not sure I understand your question. In comparing the 2010 TaylorMade Burner iron to the Ping i3+ (2003) or the i3 Blade (2004), which were the only Ping i3 irons that were Game Improvement, the difference is clearly the vertical cg location. The 2010 Burner iron vertical cg is .938″ up the face, vs .826 on the i3+Blade and .847 on the i3+. That’s a huge difference and a big reason for the difference in playability. The i3+ also has a longer c dimension. The i3 Blade is slightly shorter in c-dim, but it’s rearward cg is further back, which also increases playability. An actual vertical cg of almost 1″ on the Burner is what really reduced the playability.
Hope this is what you were looking for.