Nikon 200mm f2 + close-up tubes?

For macro and semi-macro i have the 200 f4 micro and the 300 f4 afs + extension tubes, but use the 200F2 for photographing insects and flowers in my garden and I am always very pleased with the results. As it is mentioned before this lens is capable of melting the background like no other.
Best lens I have ever used.
Never felt the urge of using the lens with extensions tubes though.