The HF-2 and W5000 are completely different headphones.
The HF-2 are open headphones with a good punchy bass, well balanced presentation, smaller headstage. They are definitely more forward sounding than the W5000. To me they are more fun to listen to and sound great with some classic rock.
The W5000 are closed and very comfortable to wear, but can have some fit issues depending upon the size of your head. The W5000 are a bit lacking in the bass, so the mids and highs tend to stand out more. The detail retreival is great and work well with classical, some jazz and female vocals.
I like them both, but they sound very different.