I expect it's very similar with the 'sonics. I can't imagine what the Clarisonic does that's worth £130 more than the TreSonic which many people seem very happy with.
That's my point really. If I'm paying £100+ more, I'd like to know that I'm getting £100+ more functionality and quality and not just £100+ more branding and hype!
People's perceptions of different products are so variable (as can be seen on these boards) which is why I was wanting to get down to the bottom line specification, really. Oh well.
Thank you all for the input.