Currently the Vault contains roughly 70 strains, numbering over 3500 beans.It's worth keeping around...
I have a couple performers that I have kept around (C99 and Blueberry Muffin) because they clone easy, grow big, and produce relatively large amounts of really good smoke. I enjoy them, as do the people I donate to. I can run a few plants of either and know what I'm getting to refill the stash. Beyond that, I want to keep working through the Vault and seeing what I have. Finding another keeper is always a goal, but it needs to be a true Gretzky to stick around.