Regarding their comparison with concept maps, mind maps have for advantage the simplicity of their shape, that enables doing very specific tasks with greater speed, but from the point of view of completeness and efficiency, their performance is more limited, and as an instrument for study and development, mind maps have the following disadvantages:
 

1. Relations between ideas are not defined, remain implicit, all alike, what disables the more important map information, if its scope is to represent knowledge.

2. The absence of relation types reduces interaction and inhibits reflection. Once the tree (or web) structure is created (there's nothing else to do than "photograph it". From the other side this is one of its points of force, though it is also valid for all other more evolved "visual" models.

3. The mind map typical schema presents a main idea, and exclusively subordinated ideas, but this schema is false in representing knowledge in any thematic filed, because with this scheme, always, most important values are lost.

4. The structure is absolutely hierarchical, with loss of representation. Conceptual knowledge is never hierarchical, but reticular. 

5. The resulting tree is never balanced, because it is not possible to foresee (or force) a uniform logical growth for every branch. If it can be forced, then there is something in the principle that doesn't work.

6. As a result, the mind map user creativity is limited and very reduced regarding concept maps and even more with semantic networks.

7. Mind maps aid memorizing, but not necessarily understanding, and even less to cognitive integration.

8. Mind maps resulting from specialized software (that-only-produce-mind-maps) have a monotonous aspect, because they always offer the same graphical model, in which only branch names change, that are attached to semi-fixed -or exchangeable- positions.

9. Mind maps are not adequate to represent the blurred nature and events of life (things are not as logic as they seem to be).

10. Connections between branches is not possible.

11. They are always incomplete.

12. They are always open to endless debate.

Anyway, mind maps have some features that in certain situations can be useful:

They force the hierarchical organization of ideas. By forcing hierarchies, it helps in a strict differentiation of ideas.
Assist to overcome disorder.
Assist in list communication.
Are convenient for construction of web site active maps (click here to see the Knowledge Master site active map).
They can be used to plan writing or to identify a book or chapter contents: see the corresponding templates in Knowledge  Master.
Mind maps can help memorizing, through typing (customizing of idea symbols) (changing the geometrical shapes of symbols, defining background and text colors, etc.).
Mind maps are usually presented as a fast and convenient way of taking notes