It depends on how complex is your model and mold. The analysis integated in SW is only useful for simple models and molds (for example, you only have one injection point available).
Mold flow in SW is to a separeted package like Comos Express is to CosmosWorks.
Solidworks 2005 Does anyone use the SW method to create mold core and cavity using parting lines and parting surfaces? I design complex plastic injection molds and have never been able to make this work well. Is it just me?
I often use my own methods, although the shut-off feature for holes is very handy even for complex parting lines and features. I can ellaborate later, if necessary, but the tools available in 05 are much stronger than before.
I make cores, cavities, and pulls all the time for very complex geometry and have been doing so since 1999. So it could be done even then, but not necessarily by using the "mold tools".