Uprated pads on rear but not front...

Solids are fine, if you run the right pad.

Don't bother upgrading rears. If anything you're making a road car worse, because if they're not getting hot they're not doing anything and it could mean a serious issue if the ESP can't save you going into a hedge because there's no bite.

Carbone lorraines have more bite than standards, even from cold. I still have the standard ones on the back though and am not planning on upgrading as I think there would be minimal benefit
 
That's pretty much what I read when I was researching. I think pagid do some carbon metallic pads too but they're more expensive