Outright paid apps will typically be shared amongst family members (since I think it's currently an Apple requirement to support it). But, IN-APP purchases are not shared, so greedy app developers tend to make a lot of things that shouldn't be (like no ads, pro version, full version etc.) in-app purchases so every family member has to buy.

iTunes music and books should share as well, if you enable it.

Has worked just fine for me. Coming from the old "hodge podge" method it can take a bit to de-tangle all your devices and settings.