Bridge or not to bridge

Bridging can offer you the benefits of mono amplifier (total separation) and higher power. However, the downside is that most (not all) amps when bridged do not perform as well at low imedances. In this case it is important to match the speaker and amplifier being bridged carefully. If your speaker performs at high imedances, then it is unlikely you will experience any of the cons typically associated with bridging. However, if your speaker goes into low impedances, then you need to watch your amp specs very carefully. For example, in non bridged mode does the amp double it's power from 8 to 4 ohms, and then again down to 2 ohms? If so, does it maintain that "doubling" property when it is bridged? Of the amps you mentioned--I don't know the answer, but perhaps others do. In the end if your speakers are low impedance, and the amp does not maintain it's characteristic watts/ohms from unbridged to bridged you are likely sacrificing quality for quantity (watts). If your speakers are high impedance (throughout the frequency response--not just the nominal), it is unlikely even if the amp does change characteristic watt/ohms that you will experience any appreciable degredation from the bridging.
Regards,

Generally speaking bridging is not the best way to go. (see reasons mentioned above) I tried it for a while with a Classe six-channel amp but eventually abandoned the idea, opting for a traditional higher powered five channel amp.

You can't bridge any of the Acurus amps. Their design philosophy was way too minimalist to allow that sort of option.