Most people will tell you that stars are all that matter for staff but that's not entirely true for CDs. Providing the CD is the same level as the manager/team it doesn't matter whether they are displayed as 4.5 or 5 stars, they will yield identical design points the following season. For Elite this is 43dp in each standard attribute (neither strength or weakness).
For Elite tier a 4.5 star who is one level below the manager/team will only yield 42dp in each standard attribute.