I want to find the holy grail of efficient and smooth...is that too much to ask!!?
That's precisely the question to ask!
Is blade chatter what edge clamping is trying to resolve?
Yes. But light razors can be noisy and rigid. My RR Lupo is aluminium, light and very audible. I initially decided it was chatter and didn't get on with it. Coming back to it a few months later I discovered everything that's good about it - blade feel, efficiency and smoothness. The light weight is something that can be adapted to. The Henson looks like it should hold the blade well enough but I haven't used one. The proof is in the pudding.