Why is it that convergence is reached when `max_update` approaches 1? Could you help clarify this, it's a bit strange to me (and the verbose output a few lines below is inaccurate as it doesn't account for this).

On 20 newsgroups it seems to stabilize around a pretty high threshold without actually converging in ~1000 iter (I didn't leave it longer, but it would be interesting to check as well). I think it would be interesting to try multiple random inits for a small number of iterations, WDYT?