Is the 35mm F1.4 worthwhile if you have the 18-55 zoom?

Depends really on how much you want from your camera system..   I have both lenses..

Yes, the zoom lens is very very good... Right on par with my outstanding Nikkor 80-200 zoom...  But, when I want to do a portrait or intimate landscape, nothing will stand between my camera and my subject but the 35mm lens.. it's that good.

MuMinded.