It's really good. ISO 1600 shots can be filtered to become ISO800 quality with absolutely no loss in quality when i did A/B comparisons directly side-by-side. Can be filtered to as much as ISO 400 with some slight loss in fine details.
It depends on what you are after and also how big are you going to print it. You control the filtration power.
If you like it, buy the registered Home version, only USD 29.90 and it's worth it. Free upgrades in the future as the product matures. The upgrades are very impt as improvements are constantly made, eg last time it took 2 mins to filter a file and now it's just like 40 seconds? After they made the program more efficient and even better in reducing noise. (faster and better in quality!).
Also lets you process in batch, better if you have lots of images in your workflow. The demo quality only allows you to save in a low quality jpg like 2MB becomes 700kb while the registered version allows you to specify the jpg quality thus full quality is possible.