You'll notice a big difference with aftermarket shocks b/c they're stiffer than stock. Plus, you'll save $ on install if you have your shocks/springs put on at the same time. I drove with stock shocks w/Neuspeed sports for a yr and my car was bouncing like a low-rider in a Dr Dre video. I then had Tokico blues installed it solved that issue. Like the others were saying, don't forget about the alignment; you may need camber kits too. GL!

 

i WOULD NOT recommend getting new shocks yet. just wait till your old ones wear out. my friend went 3 years on stock shocks with cut neuspeed sports on her 99 i4 coupe. as a matter of fact, her ride is still ok. she never got a camber kit either, and her tire wear is ok 'cuz she rotates her tires a lot. but DO get an alignment. lowering your car changes your toes settings, as well as caster, which can both wear out your tires

5th gen shocks seem to be a bit weaker. i blew mine after a year on sportlines

 

I've been riding on Sports w/o new shocks/struts. You can go for a while. Just invest in shocks at a later time.