Totally agree with you. I would add, also having owned ACT 2, that the GAT's treble is another league entirely. i remember upon first bringing the ACT2 home (which i enjoyed immenseley) that the treble was stiff...i eventually forgot about it as i got used to the other beautiful elements of the ACT2.
Once the GAT came in, the treble of the ACT2 seemed downright chilly, not just stiff. Almost strident in comparison (almost). The GAT's treble to my ear is that beautiful, fluid, and yet far more nuanced, detailed and yes, way more extended.
Enjoy yours!