Just a wee update on my RST since I fitted the E3 tail light today. Changes since 2009 as follows:-
wider (58mm) handlebars, longer (170mm) cranks, Tubus Cargo rack (also have Tubus Duo Lowrider front rack to fit when required), dual purpose pedals, Marathon Supreme 1.6 tyres, Supernova E3 front and back ...
The bike is running very sweetly now: particularly changes to handlebars, cranks, and tyres have made it even better. I have done some day runs with local CTC of 60 - 70 miles, great comfort and no problems with speed or distance.
I think that it is now the way I want it to be, no more modifications/upgrades come to mind ... for now.