Here's some info...

The theory behind compact geometry.

When they first came out, they did really increase the lateral rigidity...now other companies have increased theirs, made lighter and stiffer frames, and Giant continues to improve their frames.

If there was nothing to it, nobody would copy it...like Trek's Pilots, Serotta's Fierte's, Specialized, even the System Six and Six/13 have a slight slope to their top tubes.

Also, there are several light years between their F1 TCR frames and the Advanced frames.