Nowadays with what I fly (757/767) we try to stay pretty close to optimum all the time, climbing either 1000 or 2000 feet at a time depending on the area. In the North-Atlantic RVSM airspace either on or off the NAT tracks you may get 1000' climbs, but once in domestic RVSM airspace like over Canada, they are pretty strict on flying odd/even levels according to direction of flight.
Then again, hunting tailwind or more likely avoiding the worst headwind, you would disregard optimum for greater wind difference vs. FL
cheers,