The 'light' version of Rive Gauche is substantially different from the standard EdT: It adds an aquatic note up top and more or less subtracts the talcum powder note.
I'm no fan of aquatics, so I didn't love that part, but I also dislike powdery scents, so I liked that they removed it from the light version.
All in all, not bad, though considering how hard it is to find the light, the standard really is quite good and easy to be happy with.
If you MUST have the light version...I have a bottle I'm willing to part with (with cap and box, sprayed about 12 times). PM me if you're seriously interested.