I have found Thiel, Revel and Kef to have wide sweet spots. B&W to be one of the worst offenders for box speakers and Wilsons (Sophia 3, original Sasha) to sit somewhere in the B&W and Revels.
Martin Logans has the smallest sweet spot of all.
The only down side of wide dispersion is room interactions are stronger and the room becomes more important.
interestingly while the sweet spot is very small on B&W 800 line I feel like they had the deepest sound stage I have ever heard and seem to disappear for me better than anything else. I could not live with some of the other issues though and moved on.
Martin Logans has the smallest sweet spot of all.
The only down side of wide dispersion is room interactions are stronger and the room becomes more important.
interestingly while the sweet spot is very small on B&W 800 line I feel like they had the deepest sound stage I have ever heard and seem to disappear for me better than anything else. I could not live with some of the other issues though and moved on.