Ceramic, hands down. I haven't put them on my X yet, but I put them on my LS a few months back and every pad change I do from there forward will be ceramic.
I haven't been that impressed with the ceramics on my Mountaineer.
I recommend the combination of Hawke ceramic pads ( http://www.hawkperformance.com/ )with power slot rotors.
I recommend the combination of Hawke ceramic pads ( http://www.hawkperformance.com/ )with power slot rotors.
I However, I see little if any improvement over stock. If you think these will vastly improve your braking you will be disappointed.