OK. I have been able to really try the software on my macbook.
NoNoise is clearly not doing anything on my PC (maybe because of the lack of GPU?)
I made a quick comparison with DxO DeepPrime, with distorsion correction off (as it's clear that there are no optical correction in Lightroom for On1 DNG. I won't comment it more, considering that it will be fixed in a future version).
All exports in Linear DNG.
It's funny, as both programs are based on AI, they sometimes make completely different choices.
For instance, on one image, on the same wall, one part of the wall has more detail extraction with DxO, and another part of the wall (which seems similar) has more detail extraction with on1.
Apart from that, both programs do a very good job, I only used the default settings with on1, there was a little bit more noise reduction with on1 (a little more that what I'd want, but this is a user setting in NoNoise).
2 things that can be noted:
1) DxO maintains the color profile choice in Ligthroom. NoNoise AI does not.
On my Panasonic GM5 the files from On1 has exactly the same colors as with the "Adobe Standard" profile in Ligthroom.
On my Olympus bodies (E-M5.3 and E-M10), the files from On1 have noticeably different colors. They are not bad, just different (I can't match easily the RAW and DNG colors).
There also seems to be a vibrance or saturation boost in the images (I set all the settings to zero for the comparison, but images from On1 are very saturated).
2) When applying some strong shadow or highlight recovery, the images from DxO seems to respond better than On1.
Sometimes much better, there is some strange artifacts & color shifts in some images.
It may be linked to the saturation boost, and I cannot observe this on the test images I took from my GM5, only with E-M10 - E-M5.3
So it's probably a setting I badly choose somewhere in on1 software, or a bug. If I have the time, I'll make some more testing.
As I know quite well Photolab (I tried a *lot* of settings before finding the ones I prefer) and I'm just trying NoNoise, I won't conclude much from my trial because it's not completely fair
I was curious about NoNoise, and I'm sure that with a little more time experimenting on the settings, I'd find some that suits my taste.
I also now that the program is currently not something I'd use with Ligthroom because of the loss of the color profile choice.