This is a favorite summer soup for me...it tastes and smells like summer!!! I agree, add some lemon juice to stop it from darkening but definitely a favorite!!
If you are thinking of making this, be aware that it needs to be eaten SOON after it's made. I made a batch in early afternoon, and it was browning by dinner time. (Plastic wrap laid on the surface of the soup helps, as does adding some acid)
I love the concept for this recipe, but it really needed some acid to brighten up the flavor, cut some of the richness, and most importantly, keep the soup from browning so fast. (I added the juice of one lemon.)