Before there is renewed mass hysteria here, I'd just like to point out that this thread is nearly 4 years old. I was never convinced at the time that rust is a real problem and i still am not convinced. What I think happened with the mag pumps is that they put the wrong screws on a batch ( I still have mag pumps that pre-date the problems and the screws haven't caused any issues to this day). These screws may have leeched something into the water, but I dont think the rust per se was a problem. Also I haven't heard of any incidents regarding the use of mag pumps for years and they still use metal screws.
Regarding the Vortechs, while a product that costs as much money as they do shouldn't rust, and they were right to improve to the new design, the problem Pinkheine describes is the 1st time I've heard of anyone stating the rusted parts caused any problems---lots of fear that they might--- but I ran mine ( several of them) rusted for nearly a year with no issue with every type of animal in the system you can imagine.
Copper or other metals might cause real problems, I don't think iron rust will.