Kaizen is the japanese term for incremental improvement.
So which is better -- an incremental improvement or a big leap?
I think Jack Canfield has the perfect answer in his book The Success Principles, how to get from where you are to where you want to be. He said you should seek out both. Form habits that guarantee incremental improvement and also position yourself for big leaps (or breakout successes, as he called them). That you are going to need both. And that you should always celebrate your big leaps and as they are often like a tide that lifts everything in your life to a new level.
It is how most of us handle our employment. We try to get better at the job we have and learn on the job, while still trying to acquire skills higher than is required for that job. Positioning ourselves for some big leap.
Unfortunately, most don't handle their entire life that way. They make it a choice of one among the two. Some are all geared for a big leap. They let every part of their life run dismally in their pursuit of a big leap, a breakout success. This is an extreme that should be avoided. Others don't see themselves going beyond some set limits. They are all focused on getting better at where they are and what they do. No room for some big leap. They profess to live a focused life and deliberately shut out every opportunity for a radical change. Another extreme that should be avoided.
It is not a question of incremental improvement or big leap, but a question of how to combine the two. You should seek out both. Form habits that ensure your life is improving daily. Become better at what you do. But don't stop there. Also put yourself in the path of some big leap. Go outside your comfort zone once a while and seek a breakout success. A success that will lift all the areas of your life.