rubber vs urethane bushings

[me <ewalter@xxxxxxx>]

My wife's '73 Scout really needs new bushings for the front shackle, the 
local Case-IH wants $7.50 each for stock rubber ones, urethane bushings 
from Digest advertisers are $30-35 for all six.  I was only going to 
replace the front 4 in the shackle so the price is about the same for 
both.  For a daily driver is there a real advantage in one over the other?
Eric