Difficult to believe the 5LL suspension would be a disaster considering its on the APR4 as far as I know so I am still keen to get a kit , cart springs don't have much give when hiting bumps !
I would resist comparing one set up to another, it really depends on how well they are designed and implemented as to whether they work or not, same with the trad set up.
Jays, as you say it may have stiffer springs but I suspect not, I will ask Henry. I would have thought it would be set up with comfort and improved handling in mind, as its prime purpose was to demo it to us lesser mortals.