it's very eye-opening to play a fretless guitar -- or any instrument that supports infinitesimal micro-tones. not only is there an expected shift off the equi-temp tuning freqs to please the ear, it's "obvious" that some intervals could be broken into more than semi-tones with improved results. so a 25-step octave scale doesn't surprise me. it probably sounds very nice in the hands of a master.
-=tension & release=-