I’ve been using Topaz Photo AI since it was released. They have issues with supporting new cameras and lenses as they rely on open source projects for that support (Libraw and Lensfun). It has been an up/down experience where they break the product with an incremental release only having to fix the issue in a future release. The product has also suffered from wonky UI changes, strange artifacts, checkerboard patters and performance issues. Eventually, Topaz has corrected all/most of these and when it works, it does a really good job.
My real issue with them is their business practices and constantly changing their maintenance/update pricing. Since moving to an annual fee for updates, the terms and prices have changed 3 or 4 times, and always more expensive to the customer, now to the point that I’m not sure the price is worth the product. Come Black Friday, I’ll be saying Hello to DXO (Pure Raw 4) and if I like it, I won’t be renewing Topaz come February.