A good question. I think we agree that both ways can work well...
Usually, I do prefer the less OO style. In your example, a pure
mapping class and business logic in a user manager.
The main reason is that what you call OO style seems to enforce a
lot of arbitrary decisions.
For example, when
i would bundle them into one... but would probably split on another
level. adding items to a user may well be posessions... so it
depends. That might well be a model of User with related stuff, which
is mapped to database in another way (one2many or Relator object/m2m
or whatever), and is
