I've heard people saying that the new flares aren't as bright and annoying. With my graphics at the lowest I never had problems with flares, are the new flares better?
I tested the assumption that they travel slower or have a lower max range and that appears to be false - they have the same max range, and assuming that the bug is not affecting shell life they should also have their appropriate speeds in that case.
I cannot comment about illumination because my PC is crap and I can't have any settings on medium without having game crashes.
I did find out though that if you shoot in practice a normal flare it deploys right away like many experienced in the bug. But for some reason shooting lesmok makes the flare not illuminate at all, even when it hits max range or a cloud - as if it never even reached the arming time. (reported that too.)