Most likely bass+directivity+wider dispersion are the biggest plusses over the Ref1
Had quite a lot of speakers in my system in the last 6 years: JBL Studio 530, Kef R500, B&W 705 S2, Audio Physics Tempo 35, Kef R3, Genelec G Four, MBL 126 and right now I have the Q Acoustic Concept 300 + 2x...