Not sure how true this is, but someone at some point (could have been Gryphon) told me my amp is highly unlikely to be damaged even from a massive surge / lighting strike. I think they said the transformer in the amp will easily deal with it.
I also confirmed something interesting directly from AudioQuest today. Their conditioners are active, so if you have a Niagara and an amp on the same AC circuit, but you have the amp plugged directly into the wall, the Niagara will draw current that will no longer be available for your amp. In other words, this configuration will diminish performance. Maybe that’s obvious but I asked the question to confirm.