Has anyone ever used one of these? The manufacturer claims these filters block both UV and IR waves, which leads to better color separation with digital sensors, especially in artificial light. As far as I know, all digital sensors have an IR filter (except the M8 ). Just wondering if users see any significant improvements. Prices of the filters are quite steep.

I did so well with my Rokkor 58/1.2 purchase price I treated it to the very thin, sexy Rodenstock HR Digital series filter. These are "supposed" to be great etc. I have not tested it against a regular Hoya etc...

I use one all the time. Had the opportunity to try one in a shop and check the files later home. To me there was definitely an improvement. However the degree of the improvement might be camera dependent.