Are you refering to the rotting of the headers in Canadian winters? The old ones do not hold up to well. The jet coated ones haven't been around long enough to see any real winter activity but they look like they would hold up a crap load better.
Green 96 mystique gs 4cyl mtx
16.9 in the 1/4 mile @102500 miles
95SE in Midnight Red MTX
MSDS headers and y-pipe
SVT exhaust
SVT UIM
Optimized se TB.
Full pre 98 SVT body kit
15.741 @ 87.73mph :)
The jet coated ones haven't been around long enough to see any real winter activity but they look like they would hold up a crap load better. 
