I am currently running XP12/XP10 combo on my car. I heard if I switch to XP10/XP8 I will get better pad life. What do I give up? Is stopping power that much different?

Looking at the temp ranges of various pads I see the more aggressive ones tend to be rated for higher temps. If I upgrade rotor sizes to run cooler does that mean I can benefit from a lower temp pad?

Within each brand why would you move up or down the scale for pad selection? Does experience and tire selection play a role?