I race on other people's boats, but on my old boat (a classic '70s racer-cruiser), and my new boat (a bulbous full-keeler of less-sprightly response), I cruise as if I am racing.
In other words, I don't see any dichotomy between racing and cruising as between sailing effectively to the limits of the given design and sailing less than effectively. I have tacked sleek fin-keelers more rapidly in my full keeler, much to the horror of sporty racing types, because I know how to run my boat and because I have a great big rudder and oodles of foresail to use bring her head around. Will I win races? Hardly. Will I get the most out of the boat and belay the impression that she's a fat barge loose in stays? I certainly hope so. Any time I hear the crew on an obvious cruiser shout "Ready about?", I know I am in familiar company.
Nonsuch 30s, 33s and 36s (heavily built cat-rigged cruisers, for those unfamiliar with them) are regularly raced around here and frequently win or otherwise rank highly after the PHRF ratings are applied. Go below, and they look like nautically themed rec rooms, however. But their owners know how to squeeze potential into kinetic in their boats, and thus win races.