I've done thousands of miles with a pillion (more than 20k+ of which abroad), and in honesty enjoyed pretty much every one of them ...... then again it takes a fair sized pillion to make the handling of dinosaurs like GSX/GPz1100's worse
I think taking pillions makes for a much smoother and more considerate rider - to prevent hard jabs to the kidneys
Modern sports bikes don't lend themselves to pillions well - they sit them much higher and further back over/behind the rear spindle, further away from the centre of gravity/mass. That said I hardly notice my 13yr old on the back, and there's little better than his face after a good spin

