Personally, I would rather it break. I spent a while chasing a setup issues before I spotted the bent C-hubs. It wasn't bent by much, but it made a big difference to how the car handled (as you'd expect with 6deg castor one side, and 4 the other
). For steering components at the very least, I'll stick with the plastic
Anyway, if your gonna replace it anyway, why not replace the £4 plastic part rather than teh £15 alloy bit?