I'd like to see some more variation in damage effects/smoke rather than all the same colour rising at the same rate etc. Perhaps a 20% chance of explosions - similar to hitting an ammo bunker, rounds cooking off etc. Difference strengths of explosions, turrets flipping (see Steel Beasts) ...
A 2000lb'er in RL looks terrifying from 1000m with a massine plun etc.
Of course, if DCS took advantage of the other 5 CPUs in my system, thsi would be a problem ;) ... I know, not a simple thing by a loooooong way!
One day.