Ham,
You are right about the specs but
I have replaced 7 off 1500mm 58 Watt 5200 lumen tubes in four luminares with four of the new fittings. Light levels appear* to be 2-3X higher with good shadow fill - in fact very few shadows as such
The tubes were not particularly old but of course they do drop off in illuminance - one of the reasons for replacement as new tubes would have been ~ £5 each in retail qty's.
The LEDS have an axial 50% illuminance angle of 114 degrees which goes a long way to explaining the difference in flux levels
There is a luminance diagram on the box but a mix of feet different units and tiny 4pt print and 3 places of decimals makes it hard to interpret. best guess is 1500 Lux @ 1 M 400 lux @ 2 M
*I did once have an skip rescue lux meter but it got proper chucked... thought probably never gonna use it