I've used it a bit too. I only started investing a few months ago, so I don't have much to analyze, but it said I had close to 100% fee and tax efficiency, but that I too was too heavy on Domestic stock. I make automatic investments into a couple of Vanguard mutual funds but it seemed like they really favored ETFs, which seem to take a bit more work.
Curious- did you go with their ETF recommendations, or just use it to choose different funds?