Yue, I think that all depends on how much walking space you want. I worked with an architect and we designed my kitchen to have 3'5" walking space between the counter and the island. That isnt a small space but it isn't big either. YOu might want to go measure some model homes with a tape measure and see what walking space you are comfortable with.

As a designer, the "ideal" minimum walking space between counters and islands is 4 feet; there are always exceptions based on home owner preference. Big consideration is the amount of space you need to open refrigerators, ovens, dishwashers......esthetic eye appeal always leans on the side of roominess. Hope that is helpful.