It is rather clean, yes. It retains styles in a separate stylesheet (or internal, whatever you want) and has many blows and whistles to tune it to your liking. For example, you can specify to retain italic in the stylesheet, but ignore color usage in the styles.
It is relatively fast and does not rely on Word inner HTML conversion engine. Some things I like better in my macro, others better in the program.
The creator is also very helpful. I had a request that I could specify the styles to retain and convert all others to standard paragraph and it is on the To-Do list. I found a small bug and it was solved the next day.
One other thing that might interest you, is the option to run various RegEx after the conversion as part of the process. I use it to convert placeholders at the latest option and also to clean something up.
If you want I can convert a document for you so you can see the result. You know how to reach me.
Creator and maintainer of the e-Book Tools
Word add-in. Also see thread
here on Mobileread.
Creator and maintainer of the Clean HTML macro
for MS Word.