As you may remember, I removed all the factory suspension and ARB's from my Series 5 after having a complete suspension and ride analysis done about 3 1/2 years ago. Wish the whole thing could have been done for the £2,000 or so quoted above or better yet, that the factory had put a little more into the car at outset rather than me having to invest in the R&D to get the car right :-)
After it was completed I was tempted to try and get a GT as it seemed the factory had followed a similar route but watching the build process, all I could see changed was adjustable dampers. The ARB's remained the same. I do not know if the spring rates were changed. They were definitely very heavy weights on the S5. The rumour mill suggested they were so heavy because there were issues with wishbones with lighter weight springs. Don' know if that was just rumour or fact but on my S5 the new spring rates are set massively lighter, the ARB's both front and rear are significantly different and of course the dampers are adjustable and the valving set up specifically for the car.
The improvement is like night and day. Based on all the previous Aero's I've had and the 120,000 plus miles driven in them, the S5 out of the factory has the best steering feel and was a definite improvement of the earlier models but the suspension as standard was the worst. The changes make the car so much better. However, I think the S4 was possibly the best overall iteration of the series as an all-rounder and the GTN the most focussed.
