I tried this last week.
Advantages: Uses a SQL Server Express database, which
would be great for integration
Disadvantages: It's based on UK tax system/settings. Extremely clunky, on my machine anyway. Probably need a much more powerful machine to run it. Didn't like the UI. Huge download, even without the SQL Express stuff.
It was promising, with the SQL Server backend, but disadvantages outweighed the advantages for me. I wonder what the support is like?