The S8 is still one of my favorite "disappearing" vertical arrays. It's small size belies some pretty impressive performance.
A buddy of mine was out as SystemDude on a short tour recently, had the 55/33 rig. He called me for advice and I could offer none, having not set it up or mixed on it; he said he'd call me to say how much he hated it. He never called me.
Anecdotal, 3rd hand. I'm not sure he was impressed but he didn't call me screaming, so I think that's a good sign. He's usually on Meyer or l'Acoustic rigs...
My experience with support from RCF USA has been very good, and any questions they can't answer will go to Italy for a deeper look.
See if you can arrange to hear at least a hang of the 55 by themselves. RCF USA can point you to a system near you, perhaps, and you can pay a visit to a gig and chat with a current owner who's NOT looking to sell his rig...