So many pianists use a ton of rubato in the fugue, and romanticize it. But this as Gulda plays it is perfect. Fugues are musical structures, like an Eiffel Tower, or some great machine. They need symmetry, precision, and rock solid timing.
Bachs music is so absolute and wonderful, you can play it in many different ways ; as long you play it honestly and in a certain coherent style , its great. Including this rude performance from Mr Gulda.
Interesting. His left and right hands use different techniques. His left hand was more or less traditional. But the right hand used the more flat finger method very much like Gould.