I purchased the following - last January - so about a year and a few months old.
Stoptech Cryo rotors
Stoptech Street performance pads
Stoptech stainless steel lines.
This was a package Sport Kit
http://stoptech.com/products/sport-kits
STOCK rotors are softer, and STOCK pads are more abrasive (which cause more dust).
ISSUE: My stoptech rotors are not true, I have vibration on stopping now that is getting worse. (I have not tracked the car).
I put in a support call to Stoptech yesterday, they requested pictures, I sent the pictures posted here. The good news is their tech guy called me right away - like 5 min after I emailed the pictures. So excellent support response.
Here is what the tech said:
1) The black spots are not the issue.
2) The LINES on the rotors and the "pad images" on the rotors are the issue.
3) These lines and images of the pads on the rotor are caused by salt spray in the winter, and then the pad sitting on the rotor. This is causing a deposit.
4) BECAUSE I purchased the street sport pads, these are less abrasive than stock, hence these pads (unilike stock pads) will NOT scrub off the deposit and clean the lines/images of the pads. - This is what is causing the problem.
The tech said that if I was in California where it doesn't rain much, and there is no salt sprayed on the roads, I could have driven on these rotors and pads for 5 years and would not have had the problem.
BECAUSE I live and drive in Ontario, Canada, this combination of stoptech products was not recommended for my environment.
I should have used their Posi Quiet® Semi-Metallic Brake Pads (prefix 104) with the slotted rotors apparently. These are more abrasive and would scrub off the deposits off the rotor more easily.
I am still exploring with Stoptech if they will help me out with replacing anything. It is not under warranty which is crappy. They said because the rotor is cast iron, they don't warranty against that due to the enviornment.
My point is the STOCK rotors and STOCK pads I had on for 4 years worked great (and had much better cold bite).
I would recommend anybody looking to upgrade their brakes with Stoptech products call their tech support guys to ask what products they should actually use.
I would also recommend Stoptech put some disclaimers or warnings on their sport packages that these are not for all climates, I did a lot of homework on these products and I am now disappointed I have to spend more money to go back to stock. Not happy.