I have the Topaz suite - Gigapixel, Photo AI, Sharpen, and Denoise. There are a few tings to keep in mind
Most importantly, if you have small, lo-res images or blurry images, it's very difficult to bring them back. Thre is no magic here - the software needs detail/informatio to work with. They can help with restoring and upscaling but work best when working with a decent image.
Also, make sure you computer/device graphics card has the capability to provide full use of the software. I don't so I'm somewhat limited using some of the recovery models.. You need at minimum 6gb of vram to get best results. I still do OK with 4gb but my next laptop will certainly be an upgrade.
My two most used tools are Gigapixel and Photo AI. Gigapixel can be used as a standalone tool or as in integrated tool in Photoshop. I've always stayed within Photoshop. It does a great job upscaling images, recovering detail, and will give you several models to use including Standard , High Fidelity, Low Res, Text & shapes, and Artwork. Yu can do a split screen and compare different models to see which one works best on your image. I can't offer any opinons on the recovery models since I can't use them but the examples I've seen are are very impressive.
But,if you try to upscale a lo-res photo, you'll end up with mid jarring defects and artifacts. Rather than give up, I'll put an image thru Gigapixel to see what th result might be. Sometimes I'm surprised, sometimes I just put my head in my hands and move on.
Photo AI is great at improving the quality of the image. Bringing back detail, smoothing out artifacts and noise with options to improve lighting and color balance. You can also moderate the results with sliders if needed. Again they do have recovery options but you need the memory to handle that.
I rarely use Topa Denoise or Sharpen. Once I use the above two pieces of software, I generally then use tools like Camera Raw ,Curves etc within Photoshop to do additional work.
I own these apps but I believe Topaz has now moved to a subscription model much like Photoshop. A bit pricey but it depends on what you want to accomplish and to what degree. You can sign up for free trials of the software but the images will be watermarked.
Bottom line - I've found the software to be very useful and I'm quite happy with the results. I'm primarily a hobbyist but have done work recovering images for friends and family. Quite amazing what you can accomplish. But just keep in mind, the final outcome is dependent on what you started with.
If you have any other question for me, please let me know.