gas tanks

[old Rusty C10]

ive got a question for you all just for arguments sake.. i have a dual tank truck and i prolly have some rot in one of the return lines as sometimes i smell some gas when the truck sits and it smells back towards where the cab and bed meet
I was telling one of my buddies who is a bit of a know it all and usually he proves how little he knows the more he opens his mouth.. anyway hes arguing that i should replace the tanks i have ( standard metal) if there is rot in the with fiberglass tanks.. he says they are safer and they dont rot and are harder to damage
Is there any merit to his argument? i dont off road but i do sometimes go onto construction sites without paved roads If i needed a tank i was prolly ging to buy a cheapie from JC Whitney as ive used them before and never had any problems
Opinions???