Almost a week into the clamp upgrade, wanted to post back.
The seatpost is slipping but nothing major. A little annoying but I see this happens to a lot of users. I am a big guy and also ride semi-hard so I can't really complain - I try to de-weight the seat on bumps etc and like this its manageable. I also think (hope I am not dreaming) that it is getting better a little every day, perhaps the new seat post I had just installed had some oil / residue on it.
The drivetrain noise is not a problem, I watched many videos online and all bromptons are like this. My Dahon was a lot quieter, I guess it is just the different components being used. The Brompton is definitely of the better of the two systems, there is a lot less rolling resistance from what I can see.
Very happy with the bike, have put in about 100km's over the weekend and all is working well!
Thanks again,
Ben