We are using Words on the Vine for Greek and Latin roots. We have really liked it for vocabulary and use it for our spelling as well.
We are using WW for vocabulary and spelling and it is working great for us. One day a week I have them use each word in a sentence so that I can be sure they understand the meaning of the words. When they have to write the sentences I also combine grammar. Right now we are doing verbs so they have to circle the verbs in each sentence. It really helps save time
We are really enjoying Vocabulary Vine...and I see it working, especially in Science. I am thinking of ordering the science one, even though the boys are going to public school next year.