IMO the point of having a Cam sensor is that at any later date you can use a coil pack and also you dont have a cut and shut dizzy or a home made type item to go wrong or made wrong to start with.

The less moving parts to fail the better.

A dizzy cap
rotar arm

can fail at any point.

A cam sensor uses no parts that wear over time. Obviously the sensor will one day need replacing, but going by some cosworths that are still running on their 15year old CPS with no problems i wouldnt expect to have the same life span on our setup's.

Regards