Depends what you mean by 'more powerful.' All other things being the same, the bright channel has more gain at higher frequencies, but that might not come across as 'powerful.'
However, all other things are likely not the same. The gain of the first tube is maxed out in this circuit - so the voltage gains of the two halves of individual tube being used actually sets the gain. Differing (sample-to-sample) tube gains will have an effect on the input stage gains.