I think so. I wasn't sold on the idea when I was doing steeping grains/extracts, but once I started using Beersmith, I was smacking myself in the forehead- "Why didn't I do this ages ago!?!"
There are some advantages even for extract brewers. One is the ability to "see" the ingredients, what they bring to the recipe, and to recalculate IBUs easily. For example, if I was making a simple English brown, but I wanted to do a 3 gallon boil instead of the recipe's 1.5 gallon boil. Or if I had a different brand of extract, or crystal. All of the ingredients, including hops and yeast, are in there and you can tweak things easily.
You can save your recipes (not in the free trial, I don't think) and make notes. You can change an extract recipe easily to a partial mash, or even convert recipes from AG to extract, or vice versa.
One of my favorite features is having the BJCP style guidelines incorporated. So, if you make an Irish red, you can see if yours is "to style" and read the descriptions to see if you've met the guidelines. It helped me decide what beers I wanted to make, just by reading the descriptions, and the commercial examples!