You can debate whether you prefer SET or PP amplifiers. They definitely sound different; I think each would appeal to some. Obviously, push-pull gives the kind of advantage in power that allows most to use the triode tubes with a real world loudspeaker.
The 2A3 has half as much power on paper in comparison with a 300B, but real world seat of the pants power doesn't translate, and the 2A3 often sounds like the bigger tube. The 2A3 is also the better sounding tube, and the 45 better still. However, the 45 makes half as much power as a 2A3, sounds/feels that way (figure 3 - 6 watts for push-pull 45 amplifiers), and seriously limits your loudspeaker selection.
The 2A3 has half as much power on paper in comparison with a 300B, but real world seat of the pants power doesn't translate, and the 2A3 often sounds like the bigger tube. The 2A3 is also the better sounding tube, and the 45 better still. However, the 45 makes half as much power as a 2A3, sounds/feels that way (figure 3 - 6 watts for push-pull 45 amplifiers), and seriously limits your loudspeaker selection.