Although I still prefer my 1Dx DSLR, I'm liking my new Canon Mirrorless Camera with its ability to do super low light, ridiculous high ISO images pretty well; while being hand held. This was shot under low, ambient indoor lighting. I didn't do any noise reduction in post processing.
The main thing I dislike about the mirrorless Canon R6 is that it's a battery hog. It can use the same battery as my 7DII, but battery life in the R6 seems to be about 25% of what it would be with the 7D DSLR. Maybe less. So even with the new camera being lighter to hand hold, I can't see taking it out in the field without having a half of dozen batteries on hand for the mirrorless camera. In a way, that seems to be self defeating. Even the battery life on my tiny Canon SL1 DSLR lasts much longer. And I've always complained at that going through batteries fast.
BTW, the model is our 3 pound, Long Coat Chihuahua that we went to Italy to get. She was definitely worth that special trip. In the background is our Long Coat girl from Hawaii.