I use tubes (bellows) and close-up lenses. The quality argument just doesn't hold water under the conditions I usually shoot in - outdoors without flash.
The Nikon two element close-up lenses work very well, especially with my old 80-200/4.5 multicoated zoom-Nikkor. Magnification with diopters increases with focal length, so I use the zoom is a sort of macro zoom. Stopped down to macro typical ranges, critical sharpness is there.
Secondly, there is no light loss from extension using the tubes. There are many times where I would simply not be able to make a shot in the field due to subject motion, were I to lose another stop or two of light from extension tubes and/or bellows.