I used to be pretty meticulous about water changes and filter cleaning. I used to do about 50% water changes and filter cleaning weekly like clockwork. After reading some interesting material that suggested that frequent filter cleaning was counter productive. After all, beneficial bacteria creates an important colony in the filter that cleaning somewhat disrupts. These days, I only clean filters when output water flow is noticeably reduced.
I've slacked off on water changes too, but I have a heavily planted tank. When I did routine water changes I found I needed to add ferts for the plants. When I reduced water changes, I stopped using ferts and plants grew better! So I let the plants filter the water.
I know, some will say "Shame on You" perhaps like Byron and I did back in the day. But it comes down to water quality regardless of partial water changes. I suppose if you were so inclined, a continuous water change system would be best (like some discus breeders use) but not so practical for the home aquarium enthusiast.