I have used the rubber stock bushings in my 1/2 ton pick up with a MII with lots of miles 90K+ and with 10 years time, and the darn things wore out!!! Go figure!
I recently rebuilt the truck and the front suspension bushings were all replaced with PST ( the yellow boxes ) and the ride has not changed nor is there any noise from the bushings making any squeaks. The some of the rubber ones were coated with oil which made them fail earlier, and the strut rod donuts were trashed. If this is on a heavy project I would go with the urethane ones JM $.02