Close to ideal situation: I needed a new front tire, and Salima's GTS 23 was starting to develop fine cracks in the grooves, so a replacement made sense. Instead of two new GTS 23s or two new Michelin CGs, I opted for one each and wanted to test them alternatively with what we had in the back (Pirelli Diablo on mine, City Grip on Salima's).
First the physical stuff.
The CG and the GTS are two completely different builds. Not installed and not inflated, the CG feels like a latex glove in comparison: flimsy, soft, light. One can easily push a dent into its surface, while the GTS is rock hard. See below: