isolation transformer

Hi, I would like to hear from fellow Audiogoners what they think whether or not the use of an isolation transformer for the front end gear (CD player/DAC/Phono) is worthwhile.
According to a well known Swiss manufacturer/distributor the use of an isolation transformer has profound effects on sonics (more detail, better bass, etc.). These effects are more pronounced when using silver wire for the transformer. Do you agree with these statements? What would be better: using a smaller transformer with silver wire (say 200VA) or a bigger one, using copper wire (1200VA)? Thx in advance for your response.