Youd be talking about something like this?
Its Reg Barbers new ripple base. Ive done some searching around on some other forums and no-one really seems to understand the purpose of the ripple base apart from looking good (face it, thats not a bad photo there!) and making pretty patterns in the puck. But to the benefits in tamping? :-?
I guess like most things, you have to ask the benefits of any new ideas - they may be there to help improve performance (such as the clicking device in the Espro or the TrueTamp rings in the Pullman models), or like copper bases and highly polished surfaces they may be there purely for aesthetic reasons and to look fancy in photos. You might like to have a read through http://espressorun.blogspot.com/2008/09/reg-barber-ripple-tamper-evaluation.html which has some nice photos of this device, but likewise doesnt really shed any light on the benefits of the ripples apart from the aesthetics.
The only thing I think it could possibly do is if you have a heaped basket of coffee it will very slightly distribute that heap into rings, a bit like what a convex is supposed to do but less effective - so you get concentric rings of high pressure, low pressure, which to me sounds like a good recipe for channelling. However the rings arent too deep so whatever effect they have would be fairly minimal compared to a smooth tamping surface, especially once the puck expands up to the showerscreen. A number of years ago I considered making a base with a spiral in it to help distribute the coffee smoothly but decided against it because of the disturbance it would make to the puck surface. I guess this base would be less likely to scratch than a smooth surface since not much metal is actually touching the bench but that hardly seems a good reason to create a vastly uneven tamping surface.
There may well be design reasons for the rings so take my comments in the context of my inability fo find any concrete information on the benefit of this, and in that of my understanding of the whole purpose of a tamper - that is, an even compression of coffee. Perhaps in due course the manufacturer of this tamper will put some info on their website claiming its benefits.