[RWebb]

FG will last longer than vinyl as per a post above, so in that sense is stronger

vinyl is also a high pollution product (affects people who live near the plastics chemical plant - if you care)

and vinyl outgasses vinyl chloride into your house, a toxic gas (got kids? how well is th house sealed?)

FG may give the house better resale value if you don't stay long enuff for the vinyl ones to start cracking (more common in Calif. than Ill.)

seems to me that vinyl windows also stick and don't slide well