Like Kirsty, I only do underpaws, as I like to see the full coat. I had used to trim Izzy's slippers. though as they grew long as though they had fertilizer applied.
Teddy lost most of his undercarriage coat, chest hair, side skirts , leg feathers and bum hair, due to his allergy, but since treatment with Atopica (in October/ November ?) all is back to normal , except for the side skirts which haven't grown as quickly.
I know at least two people who had the whole dog trimmed, to find that the coat grew back curly. (One Blenheim and one tricolour).
Barbara, Monty, Joly and Teddy.