Topaz Studios has enjoyed an expanding reputation for well done innovative plugins over the years, often being ahead of the game particularly when it comes to the new Artificial Intelligence plugins.
Denoising is now standard is many image editors but Denoiser AI is a step up from most of them, while suffering from the same setbacks that I don't think you can really get around. Some images are just too much for any software, AI or not, to just make up large areas of ambiguous pixels. Overall the images can be greatly improved and if the problem is just grain from lower light but otherwise detailed images it does an amazing job. One thing I found was if you have already demised the image somewhere else, this plugin can't do much more with it. This makes sense as the image has been "smoothed out" so the grain has already been removed so there is little left to read. DXO Photolab has the best denoiser I have seen but it only works on RAW files while Topaz plugins work on any number of formats.
Another issue was integration with Affinity Photo. It can do it... but not if you bought the app from the Apple App Store. This is a problem with other plugins as well and the reason when Affinity goes to Version 2.0 and charges for updates I'll buy directly from them. I find the Apple Store updates lag behind the ones directly from Affinity by up to a couple days as well. Luckily, the Topaz Plugins also work as independent applications
4x enlargement with original for scale.