From the FS-WWI Website:
"This is the 2nd incarnation of Gypsy9's excellent repaint of Somme. You will find the colors more vivid, the buildings placed properly in the towns and airfields, and overall a much improved look of Somme. This is MUCH smaller that the original Somme Repaint. However, you do NOT have to have this download if you've already installed the FS-WWI On-line Standard. Having or not having this will NOT make you incompatable on-line."