That's true, the 7000 does have gold types and ground types where it does have the advantage. With the flat winds the greater performance increase is seen in the smaller coils, 11 E & 12 NF. Reason being as all coils have the same length of windings in them, an 18 inch has the same length as an 8 for example. Meaning as a coil gets bigger the windings get narrower, less surface area in width. This means that the percentage of performance advantage of say a flat wound 12 vs a standard 12 will be greater than that of a flat 18 vs standard 18. The performance increases therefore vary depending upon the coil size. Big increase with the 12, let's say 20% for example, but less on an 18 say 8%.