I am buying a C&L intake and tune from Brenspeed. I was also thinking of buying a coast alumnum diveshaft. Is the driveshaft worth it, or is there a better mod to spend that $550 on. I don't want 4:10's either.

Thanks

 

I like the spyder shaft better

 

I have the Coast 4" aluminium driveshaft. It wieghs 18 lbs. The stock DS weighs 42 lbs. Removing this amount of weight from rotating mass will make a much bigger difference than removing a similar amount of weight from any other place in the car.
It makes a noticable difference. The car feels "lighter" and accelerates better.
Also the single peice DS is much less complex than the factory two peice assembly and therefore stonger and more reliable. One less u-joint to wear out and no hanger bearing. I would not trust the stock DS to handle much more power than the car came with so if your car's future has mods in it I would consider this a very worthwhile upgrade.