i have glass fenders, not sure if they are glastek because i got them from a member here. this was 3-4 years back so they were just coming out with glass fenders, alot of work to get them to fit right, i don't know if the fitment is better but if you're doing a show car- go with steel, it will be easier and looks better.
my car sees maybe 500miles a year cruising, but a lot of track time. the glass is holding fine.