A little more detail on the "Wikistats 1" metrics and how they work in Wikistats 2. From the start in Wikistats 2 we allowed as much flexibility as we could to filter and split in different ways so that you could explore the specific data that you cared about. A few people asked us for the ability to filter or split on multiple things at the same time. We will work with a designer to get that UX right, but in the meantime we took this step. What this does essentially is pre-filter a Wikistats 2 metric the way it would have been done by Erik's scripts in Wikistats 1. And we've hidden the dimension that we're pre-filtering by to keep the metric true to what Erik had. We've also linked back to Wikistats 1 so you can compare numbers and ask us questions when they don't match.
Let's look at one specific metric, "Active Editors". What we did was pre-filter the "Activity Level" options to only count editors making 5 or more edits. There will still be slight differences between the Wikistats 1 numbers and ours, but they are close as far as we could tell. Do let us know (via the link Nuria mentioned) if you see bigger differences.
And do let us know if this makes sense or if we could explain it a little better. Our goal is to make sure everyone using Wikistats 1 can transition to Wikistats 2 without missing important data or features.