I have just got Kelly fretless and getting ready to take it to my luthier. I have read every thread on TB about strings for the fretless abg's and I am down to TI acousticore or the jazz flats. The D'addarios that came with only sound good while amp'd and only on the lower notes. I will be using this for practicing at night and getting together with my acoustic guitar friends. I do not expect it to be loud enough to play with other people. Can someone help me with what would be the fundamental differences between using the 2 strings? I would like to get more of an upright sound but do not want to get one dimensional in my sound.