According to OSRAM, the Cool Blue Intense H15 is dimmer than the "Original Line" H15, at 200/1330 lm compared with 260/1350 lm. :-(
See https://www.osram.co.uk/ecat/COOL BLUE INTENSE-Halogen headlight lamps-Car lighting-Automotive/gb/en/GPS01_1056960/PP_EUROPE_UK_eCat/ZMP_1191016/
and https://www.osram.co.uk/ecat/ORIGINAL LINE-Halogen headlight lamps-Car lighting-Automotive/gb/en/GPS01_1057023/PP_EUROPE_UK_eCat/ZMP_61174/
I don't see how they can claim "up to 20% brighter" when no member of the Cool Blue Intense product family has a greater luminous flux than Original Line product family, but they do have a significantly reduced lifespan, as listed on the PDF family data sheets.
I don't think 30% brighter bulbs are noticeably brighter, but if there was a 30% brighter H15 available I'd buy it.