Clear Gesso: Does it produce a translucent foundation layer?
I've used the clear gesso with pigments to create underpainting. Clear gesso mixed with acrylics can achieve a faux watercolor paint effect. (I found an example YouTube video here.) I personally did this a little differently. I mixed the clear gesso with the paint in a little cup and added a few drops of water. I dipped my brush in the paint and painted over dry gesso. (It had a similar effect, but I had more control.) 

To answer your question; It is definitely translucent upon drying and would make it more difficult (but not impossible) to achieve an even-toned background. If that is what you are going for, I would definitely stick to the white gesso. But, give the clear gesso a try. I highly suggest experimenting with it!