K&F magnetic filters - CPL, UV, ND1000 - Excellent choice !
Packaging : 6,5 / 10
Nice case that keeps the filters together and protected. With velcro and ring to attach it to a belt or backpack.
I don't particularly like the plastic box, I would have preferred something ecological like for other brands, but it's not something important in use so it weighs less on the judgment of the packaging.

Handling: 9,5/10
Excellent workmanship, the filter is metal, threaded which fits well into every lens in my possession.
Great that they are magnetic. In some conditions, screwing on a filter is very difficult and time consuming as well as the risk of it slipping out of your hands. In the case of the K&F magnetic filters, you just have to leave the holder mounted. If necessary, simply move the filter closer to the lens and it will attach itself powerfully and precisely.
This feature is the main reason to buy these filters.

Optical quality: 8/10
ND filter: Excellent sharpness: there is no loss of quality in high contrast areas. As with most ND filters, the filter has a purple/magenta cast, nothing that can't be corrected in post-production (see photos - doesn't work on PC just to show the quality of the filters). Slight vignetting, but really slight, nothing major. Score : 8/10

Polarizer / CPL Filter: Very very sharp filter, no loss of quality when editing. It tends to slightly "warm up" the images, but again nothing that can't be corrected with a touch in post-production. Excellent reduction of reflections on water and leaves affected by bright light. I don't like the effect of the sky being too intensified towards the Blue color (which also happens with all the other CPL filters I've tested). Important note in this case, it does not produce any additional flare compared to a use without filters

UV filter: I never use UV filters because I find them useless except in case of danger for the lens (salt / water splashes / resins, sand). I must say however that this one has a good performance, it does not lose sharpness or worsen the flare compared to the lens without filter.

Quality/Price: 9/10
For the general quality of the filters in question the price is LOW.
Such a kit is suitable for both demanding amateurs and professionals because the weak points of these filters are few and in any case surmountable, while the strong points (speed of use and sharpness) are more important.