I am currently only owning the base game. I was thinking of subscribing to the "all DLC" package. But after playing the base game for a while, I noticed that I was unable to excavate any geological sites. A quick web search told me that this is a known bug.
Now I'm really unsure if I want to spend any money of this game, given that it contains such an obvious bug affecting already the early game. Is this bug representative of the current Stellaris experience? Or is it an exception, and if I continue playing I won't run into obvious bugs like this again?
Sidenote: it was impossible to post this in the official Stellaris forums, because they think this question is "spam" or "inappropriate".