I actually prefer lightning, Sun and Moon rendition, clouds and weather effects overall in IL.2 Battle of to DCS, at least in their present versions.
Maybe version 2.0 of DCS can make my mind ( ? ).
Then there's that much more plausible identification of distant objects, particularly aircraft, in IL.2, compared to the various approaches used in DCS.
The only negative aspects in terms of scenery rendering in IL.2 are those derived from that awful "hallo of mist" around the aircraft, particularly noticeable the higher you climb, making realistic use of operational altitudes for some missions useless, IMO...
I really hope 1C / 777 finds some way of getting rid of these effect in future releases.