I've got a 2002 wrx wagon with 24mm ARB front and rear, white line ALK and white line droplinks front and rear. I have eibach springs fitted atm, they have been on the car for over a year. the ride has always been a bit harsh with the eibachs, so much so that im thinking of going back to the oem springs. My question is how much will changing the springs back effect my handling?

 

Had the same mods as you,on an 02 wagon-using perrin items and tein springs.It all looked nice,but the suspension was way too harsh.Took some advice from Thwaites- bought some prodrive springs(TSL on ebay did a great price) and ditched the ALC.
My car handles well now,looks good(not as low as when using the Teins) and is only a little bit harsher than running oe suspension.
Personally,i would ditch the ALC and keep the springs and see how you go from there.