I say, BOTH. Why? Because if you can't be happy about what you create, nobody else can either.
I became dissatisfied with some of my realism paintings. In fact, I realized that I would not want to hang them on my own walls! Now that is quite an admission.
The reason for my displeasure? Some of my realism looks like photographs - sharp edges, bright colors, lots of contrast. As I have found over the past two years managing the Gallery at 11 Pleasant, people love to admire such images, whether painted or photographed, but rarely do they buy them. They are simply too "in your face". So I found myself drawn to artists' work that was more subtle, less bright.
I'm happy with the tonalism works I've been making; yet I still like to do realism. The painting above is an example of the kind of realism I am doing these days. As you can see, it's soft and expressive, yet has a lot of depth. Notice the strong contrast between the dark distance hills and the crest of the field beneath the tree. That is the sweet spot, one of the ways you create depth. Another is "fuzzing out" those distant hills with a neutral color, which depicts atmospheric density.
Let me know what you think about these changes in my work. Your opinions matter!