I thought that the edition 30 had a crashy suspension as standard. The pss10's were better in every way imaginable. On the softest setting they were more comfortable and less crashy than stock and gave a better feel to the car overall. Add to that uprated ARB's and the difference was superb. I'm not saying the stock suspension was bad, just not good and definitely not optimised! The brakes were "adequate" for a stock ED30 but a mapped ED30 definitely needs more substantial brakes than the OEM ones.....unless you drive Miss Daisy around, and if you drive a mapped ED30 I'd expect 100% of you will at some point drive it faster than a stock one would go at a given point on a road.
As for tyres, a car is only ever as good as the quality of the contact patch between the road and the wheel. Putting cheap/poor tyres on a sports hatch is like putting Ronaldo in wellies!