I downloaded a free 10-day trial of the Serenity Editor for Writers and Teachers. It combs through your ms to point out ways you might be able to tighten and polish the prose. It also does things like homonym check, spell check, and cliche check. It doesn't do the work for you -- just makes finding ugly writing easier.
I'm in the home stretch for my latest book and so far I'm impressed with it. It's far more advanced than MS Word's built-in tools. For $55, it's
almost like having your own copy editor.