One of the stats I like to keep track of during my lager fermentations is the average gravity/day drop during the first 7 days after pitching. This gives me an idea how well the yeast is doing. For most lagers I can get 1 Plato/day.
Another interesting yeast characteristic you may want to look at is: “how close does your yeast get to the terminal gravity?” Terminal gravity is the gravity of a fast ferment test and may or may not be the final gravity you want to get. It does however tell you where the yeast has to stop b/c after that no more fermentable sugars are left. I, for example, experienced that WY2206 and WLP833 are having a rough time getting those last sugars even if they have been performing well during the first week of primary fermentation. For some beers, like bocks for example, this is desired as you want some residual fermentable sugars. But if they stall too early the beers will be too sweet. WLP 830, on the other hand, seems to have a much easier time getting to the terminal gravity and is thus a much better choice if you want beers that finish dry (Pilsner for example).
Just some food for thought as you are pondering the yeast behavior during your lager fermentations