Advantages (+)

• Enables abstractions at the finest levels.
  • A small number of physically created objects can represent an open-ended number of logically different objects.

Disadvantages (–)

• Introduces run-time costs.
  • Clients are responsible for passing in extrinsic state dynamically at run-time.
  • Storing/retrieving/calculating extrinsic state each time a flyweight operation is performed can impact memory usage and system performance.
• Provides no reliability on object identity.
  • The same physically created object represents many logically different objects.
  • Therefore, applications that depend on object identity should not use flyweights.