Sorry for all the post guys, just tryin to learn bout these things before I invest my money into sumthing, so which one would you get?

Polypropylene is stronger

1998 Eclipse GS

AEM Intake
Freedom designs strut bar
Eibach pro kit
Greddy cat back exhaust
High flow cat
APC indiglo gauges
Indiglo hvac gauges
Gen. 2 Altezzas w/ painted center
GTS Solarwing painted
APC clear side markers
PIAA superwhite lights

Stereo:
Kenwood cd player
kenwood excelon 6.5" components in doors and rear panels
diamond audio tweeters in dash
Dual 12W3 JL Audio H.O. box
kenwood ps 300 amp for subs
eclipse 4 channel amp for mids and highs
2 .5 farat monster caps and monster cable wiring

x-mas gifts that aint on yet:
Mesh grill
carbon fiber euro dash
18" katana concept 7's
Greddy header

future mods:
chrome engine kit

As I understand, polypropylene is also heavier, and as a result, less efficient (not as loud at a given power level) compared to paper. Maybe someone can confirm if this is true or not.

Titanium ;) Eclipse makes them too, what a coincidense ;P

Well it kind of depends on what your're looking for. Lam paper is lighter, but that doesn't mean it will be more efficient. Paper is more suceptible to UV light damage and also moisture damage, although the laminate helps some. Polyprop is stronger, lasts much longer, and is not affected by moisture or the sun. But if you want the best-of-the-best, go with aluminum or titanium. I have 2 15" Eclipse aluminum cone subs, and they are nearly indestructable! They also act as a heat sink for the voice coils, so its very difficult to blow one of these subs. They are more pricey though. Go with poly.

i wouldn't base my choice on cone material. There are companies winning tons of competitions with paper(ie image dynamics) and pp(ie jl audio). Choose based on what you hear and like and/or the reputation of the company.