I put ceramics on just before Christmas and it was fine all winter. I drive just over 5,000 kms a month so I had lots of time to test them. PLUS I was also driving in -40 weather for just about most of Jan and all was fine.
NOW for the rotors
About a month or so ago I installed SLOTTED rotors from RSM racing. After break in period ( they told me about 150 kms) I tested them. They "claim" that it will reduce your stopping distance by about 10 feet, I have to disagree I think they decrease your stopping distance by more than 10 FT, these things are AMAZING. I put them to the test once again last night.
I was clipping around a few really sharp corners faster than I should have been, then out of the corner of my eye I see something on the side of the road. It was a wolf, I hit those brakes and it felt like the car stopped in it'* place. Gave new meaning to the term "Stop On A Dime".
So if you are looking at changing the rotors also I would seriously look at those slotted ons from RSM racing, Ty From www.domesticperformance.com
sells them along with allot of other companies out there. I picked mine up right from RSM since I was around that area when my rotors died. They told me that they have a higher Kevlar content in them to resists heat better than most rotors.
Sorry for the long post but just letting you know personal experience.
( btw, these brakes are installed on my 2003 Malibu, I wouldn't' put my Bonneville through that much mileage a month for work, lol).