I've never found the brakes a problem TBH, maybe it just depends what you are used to. French diesel engines are generally indestructible so i assume the dCi will be reliable for you.
I have found the 88hp 1.4 to be fine for around town and great on the motorway but i couldn't say how the diesel performs. The power is similar but obviously the way it's delivered will be different - diesels are always a bit slow off the mark, you have to learn to use the torque rather than the power.
Katie, clutch control on a diesel should be a piece of cake so it's interesting that you found it a pain, but as i say i've not driven the k12 diesel. in my old peugeot i used to be able to set off from a standing start in 3rd - impossible to stall!
