Here are the [results for the wider grid](http://nbviewer.ipython.org/urls/raw.github.com/ogrisel/notebooks/master/Parameter%20search%20for%20Extra%20Trees%20on%20the%20MNIST%20classificationt%20task.ipynb) (same notebook, updated). `max_features=100` is slightly better but the change is not significant. On 1000 trees I get 0.0243 test error. Training 1000 trees with `max_features=100` is much slower than the example though.