Any top pro will tell you that you should match the optical quality of your filters to the optical performance of your lenses.
Inexpensive filters are fine for inexpensive lenses, but on a good or great lens they can cause loss of sharpness, aberrations in image quality, unattractive colour casts and more.
Hi-Lux filters are tough protective filters. And, unlike any other protective filter on the market, they are made from the same quality glass used by NASA, so there will be absolutely no loss in sharpness or image quality, no matter what lens you’re using.
Hi-Lux controls ultraviolet light, optimizes quality, contrast and edge separation between colours, and can improve peak acuity and chromatic clarity. It warms slightly less than an 81A filter, which makes it very effective in bright sunlight, with electronic flash and at high altitudes.
You know how good the equipment you shoot with is. Are your lenses worth protecting? Is image quality something you’re willing to compromise on? What it comes down to is not whether a Hi-Lux filter is worth the cost, but whether its optical performance and peace of mind are worth it to you and your photographs.