Recent Shearborns are essentially upgraded Emotivas but sonics should be extremely close. Previous versions were quite different. I own one for my center, heights and surrounds and can not complain but have not tried it for my mains so really have not tried to evaluate.
Main Kef: Reference 205/2 & 202/2c, Surrounds: Kef XQ40, Velodyne Optimum 12, Integra DHC 80.3, Ayre K-5xeMP, Oppo BDP-103, Bryston 4Bsst2, Parasound Halo A31. Second B&W: 685 (3), CCM618, Def Tech Powerfield 1500, Onkyo TX-NR1008, Zone 2 Klipsch AW650.