Personally, i prefer to write it all in my own words. My english used to be really bad when i was under, but in the last two years i have had an english tutor and i have had a really good english teacher at school and i have improved my english skills. Now my writing is better then ever and i can make my work even better.
But for most you guys i assume english wouldn't be your primary language, so this tool would be ideal for you - i don't want to sound like i am being rude in saying that either
But in saying that, writing it in your own words improves your english skills.