Not sure about the others, but with the Eibach prokit was hardly any noticeable difference from standard on my Giulietta in terms of stiffness.
I would probably put them as the softest, but I don't feel qualified to put the rest in order.
After the experience I had with Apex springs on my Fiat Coupe I would advise you to avoid those if you come across them. They were badly formed at the top, so that the coil bearing didn't sit correctly. The bearings then made a noise when the steering was turned. They would make clanging noises over bumps as the coils hit each other and to top it all the car didn't look any lower than normal.
Giulietta 2.0JTDm (170), BMW 335i Cabrio