Hand stripping will always bring out a better coat, clippers I have found in the past as already stated by Printer brings out a fluffier, lighter coat.
Saying that, I clipped both my dogs at the beginning of summer because it was easier and gets the coat right back to the skin and cooler.
I have been stripping them over the last few weeks and the coats are improving, when the working season begins proper, good hard work keeps the coats down anyway. Tight earths, bushing and hard work does it for the winter.
I have a pup for sale out of Milly and Jack if anyone interested please PM