The rule I use is to use the smallest amp that will do the job. For example, when I decided to buy a Musical Fidelity integrated amp I had a choice of 4 generations with each generation having more power and more output devices. I chose the oldest and simplest one because although it had the lowest power it still had more power than I would need. But a choice like this is seldom available. I have been looking at the C-J 350 transistor amp. They do not make a comparable lower powered version of it. So it all depends, but if the lower powered amps in a range meet your power needs and they are of comparable quality with the more powerful I would go with them.
