I love the stats and the incentive they provide for improvement.
Here's a suggestion for your consideration, Alan:
One of the stats categories is 'Largest Words' which measures the number of seed words you find. Since Chi now differentiates between common and rare seed words on the scoreboard, it would be useful to also differentiate these in the stats. Also, instead of measuring the number of seed words found per puzzle, I'd find it more informative to know the percentage of possible seed words I've found in both categories (common and rare) in the same way as we get a percentage for total words found and rosettes.