What do I gain by going to 'performance' front end parts?

Mopar to ya said
More what? Responsive handling or steering? I really don't have handling issues. I'm really trying to understand the gains and if they are worth so much more money. Keep in mind that this is almost a daily summer driver for me. It has yet to see the track, though it will on occasion. Other than that it's a normal street machine.

so far on my 65 satellite (440 auto) I've seen this. I have PST poly bushings and all their kit in it. It's tighter than it was (suspension was really bad) and has a solid steering response and is supposed to last longer (it transmits more road noise to the inside of the car though) it did squeek but that was my ault for not lubing the poly before install, took it back off lubed it and all was good. it has Gas shock all around
this car does see some track time.
I just did a friends 70 challenger with stock parts and gas charged shocks , all rubber and no poly. it seems that it tightened up his car also.
Driving his car is just as smooth as the 65's and quieter no extra noise other than the normal engine noise. (440 six pack 4 speed)

My choice on the next car (66 dart convertible) is Rubber because it's going to be a DD(and I couldn't find offset bushings in poly). I can't see the quality difference unless your pushing your car in either track or road racing twisties. plus I figure that if the originals or replacements that I took off the car lasted 199,000 and 40+ years and that even if I put on 30k (not happening) a year driving the dart it'll be another 7 years till I gotta do it again. then they'll probably have come out with some other material that last's even longer than poly.