Gosh, I have purchased several packs for the worlds, a couple because I liked the main features, a few for the BB stuff, one or two just to be able to download lots I wanted and certain packs were required to be able to use the lots. And there are a few packs I will never purchase because nothing in those packs appeals to me on any level. Generally speaking, there is usually something to be gained by having certain packs. Whenever the main features in a pack prove to be buggy, I wait until the modding community has time to fix it then purchase the pack when it pops up in a 50% off sale. But in all truthfulness, I feel the free game updates have added just as much to the game as most of the packs have. Especially in 2020.
