Agreed on CC6
Used it on two cars

It’s quiet and comfortable
But under-average dry grip, terrible wet grip

Driving in the wet always scares me

Never tried XM2+, but I used XM2 previously and it’s definitely long lasting with slightly better performance compared to CC6

Wet grip isn’t great either but not as terrible as CC6

Currently on Pirelli P1 Cinturrato. They’re not bad. Decent noise levels, decent grip

Not sure how it compares to XM2+