Custom types are good for objects with the same set of properties.
Arrays are good for a whole bunch of items of the exact same type.
Look at it this way:
P1 P2 P3 P4
Lives x x x x
Score x x x x
Name$ x x x x
Using custom types, you use the columns, and end up with 4 players, each with 3 different fields.
Type Player
Field Lives
Field Score
Field Name$
End Type
Or, with arrays, you use the rows, and end up with 3 arrays of 4 elements, and each index belongs to a player.
Dim Lives(4)
Dim Score(4)
Dim Name$(4)
In this case, it would make much more sense to go with custom types, since the objects all share the same properties.
If, however, you're asking "linked lists" or "arrays", that's another question.