MylSAM engine provides simplicity, use less system resources and is much more faster with huge amounts of data.
MylSAM doesn't allow to perform more than one operation at same time (Table Transaction Global Mutex), poor data integrity and security.
InnoDB is the best choice where all data is correlated (PK/FK and FN) ,indexed and where have chance to perform one more operation at the same time.
This provides data integrity and security.
InnoDB use more system resources and have performance penalty with large amounts of data.
Sry for bad english