How Durable are the New Plastic Models?

Are the new plastic Venatari and Custodian Guard Sodality models pretty durable, or do their lances and spears break easily? I'm trying to determine if it's worth going through the trouble to magnetize the weapons to make breaking less likely. Long, thin, weapons that extend from the model tend to be vulnerable, but I'm hoping to avoid having to go through the extra effort, if possible.