I'm not sure I get the "RS vs ED30" comparison, as far as to suggest you could buy a 3 year old ED30 and spend £x,xxx modding it to beat a standard car. What does that prove?
Think back to what an ED30 cost new, spec it accordingly, adding whatever Recaro CSs were as an option on R32s and then the cost of all the parts and fitting to make an ED30 go, stop and corner - you're WAY over £30k.
1/4 mile action means cock all to me. The fact the standard RS was a second quicker round a track than Revo's Leon means everything. The Leon is at the top of its game power wise on a KO4, suspension, brakes & other mods... the RS still has masses of headroom for improvement.