Hall sensors

[Crank]

As I had to change my seized alternator I took the opportunity to replace the cam shaft position sensor. I was getting the engine management issue light coming on ever more frequently and the fault code was for a faulty cam sensor.
The original Bosch one is much more expensive than most of the alternatives so I bought a Facet one as its only a magnet after all. However on comparing the replacement with the original Bosch one I could see the magnet is half the size on the Facet one. Does it matter? Will it therefore send a weaker signal, or does it mean it will fail more quickly as the magnet will loose its strength sooner?
I have, of course, also changed the belts, tensioners and water pump.

[junior]

I found my distributor would not advance when the magnet was put in upside down so it may have a big influence in your cam sensor. Good luck.