Broadly speaking, there are often a lot of other design variables between two SS amps beyond just the bias level of the transistors. A lot of the high end Class A amps are designed to have very little feedback, which enhances the high linear accuracy of Class A, but often at the expense of slightly higher noise and lower damping factors. That tends to create a certain sound which I personally feel is a bit closer to the typical tube sound. On the flip side, it is more common for the Class AB amp designers to use some amount of local and global feedback, which "can" marginally impact the linearity, while reducing noise and increasing the damping factors and tightening the bass. In my experience, it is very hard to generalize that Class A sounds better than Class AB since there are a bunch of other design factors that have to be considered. The typical Class A amp may sound different than the typical Class AB amp, but it's not always better...
