After playing round wound strings for years, on fretless, they wore ruts in the rosewood fingerboard. After the fingerboard was sanded smooth, I bought nylon electric bass strings, but they had a high tension at standard pitch, causing pain in my fingertips as I pressed down. So I strung it with heavy gauge flatwounds and enjoyed the warmer and deeper sounding bass tones - light and heavy gauge strings are different states of mind. They changed my playing and I've used them ever since. They sound mellow as they age, like a woody, thunking sound - hard to describe, but enjoyable to hear. But, roundwounds certainly have high definition and brightness and if they are light gauge, one tends to play more notes. However, I found that the roundwounds required more frequent replacement as they lost tone with age. You almost need two basses...