I have a UV filter from Hoya used in the Super HMC version many years. As a UV filter is not needed for digital sensors and I have been through critical reflection and maximum magnification of the opinion that the filter minimally detrimental to the optical performance of the lens, I am finally "landed" at the B + W Clear Filter.
B + W filters are without exaggeration Topp! That makes you feel even when attacking. The glass is firmly seated in the frame and does not have a micrometer game. The version - although in an extra low height made (and thus also ideally suited to super wide angle lenses without additional visible vignetting would be the result) - is rock solid and robust. When screwing in the high manufacturing quality will feel and hear. The multi-layer coating is top notch.
On the imaging performance of the Clear filters B + W have no visible impact. Normally I get barely into raptures, but in the B + W products I am just thrilled. The filters are worth their price. Therefore, a full five stars.