I really like the quality of K&F. I have another VND from them as well ones from Neewer and Freewell. So comparing this one to those, there are a lot of things that I like and just a couple that I am not too crazy about.

I love the build quality. The movement is smooth. The handle makes it really easy to do a micro-adjustment. The case is one of those nice PU leather ones with the ribbon. The hydrophobic coating works great. I dripped a few drops on it to test and they just roll right off. I touched it with my finger and couldn't tell where I touched it.

As to the quality of the photos, I don't notice any color cast, although I do shoot with auto white balance, and also don't usually need to take the filter all the way to 9 stops. I used this on my 35mm 1.8.

The only things I don't like as well is that this is a beefy filter. I prefer to have a filter case with me because I have some pro mist filters and some creative filters. This one is just thicker than all the others. So I have to watch how I stow it in my bag. The advantage with a filter that is a little bulkier like this is that it is easier to thread on and off. Also, I know the description says it is stepless. This is fine. But I would prefer a slight tactile response to each step. And it would have been nice if there were a hard stop at each end of the range.

Overall those are minor nitpicks and are mostly just a preference. This is an extremely well-engineered filter and is the nicest one that I own. I have really enjoyed shooting with it.