It amounts to trade offs between size, current drain, speaker size, tolerable distortion and product appeal. Anything with class A output uses more idle current. Note the batteries on the 447.

I replaced the half-dozen electrolytic capacitors that all measured at least twice their rated value and that improved things quite a bit. Touching up the alignment made things even better. For a 4-transistor set, it does fairly well. After dark, I'll see how well it does on distant stations.