Who has replaced factory sub with aftermarket (factory box)????

[JAR1299]

Ok,.....question for those of you who have replace the factory sub with aftermarket one using the stock amp/enclosure. Does it make the sound better much at all?? I know it won't be any louder....but I'm not looking for that...I just want the sound to be cleaner. Right now with it all factory when I turn the volume up higher the sub starts to distort. The 2 subs I'm looking at using are either a Kicker Comp RT Shallow mount dual 1 ohm voice coil sub or a Rockford Fosgate P3SD4-8 8" Punch P3S Shallow 4-Ohm DVC Subwoofer. The factory sub had dual 1ohm voice coils so I could plug the Kicker sub right in...and it is vary shallow with only 2 11/16" mounting depth.....the RF I'd have to wire differently than stock and it's not as shallow. So...I guess my question to those who have replaced sub while using factory amp/emclosure....is it really worth it??......does it clean the sound up much??