Well, since this is just about to fade off from the current thread status, I will give you some "second hand" information. When I was shopping for my current No. 23, I spoke to a guy who was using two No. 23s bridged for mono, (he was selling one as he no longer needed it.)
He said that the sound was virtually identical in the unbridged mode.
However, he had one big warning: If the speakers being used have low impedence, by that he said anything less than 4 ohms, he said the amps would really overheat fairly quickly and then shut down. So be aware of this possiblility.
(By the way, I used to have the No. 27 and upgraded to the No. 23. I loved the sound so much, that when it came time to upgrade for more power, I just went up one notch! I wish I could have afforded to 23.5, but just did not have the money at the time.)
Hope that helps.
He said that the sound was virtually identical in the unbridged mode.
However, he had one big warning: If the speakers being used have low impedence, by that he said anything less than 4 ohms, he said the amps would really overheat fairly quickly and then shut down. So be aware of this possiblility.
(By the way, I used to have the No. 27 and upgraded to the No. 23. I loved the sound so much, that when it came time to upgrade for more power, I just went up one notch! I wish I could have afforded to 23.5, but just did not have the money at the time.)
Hope that helps.