What is the Difference Between the GPX 4500 and GPX 5000?

Question: What is the Difference Between the GPX 4500 and GPX 5000?

Answer: GPX 5000 has 2 coils, GPX 5000 has 8 soil/timings, Salt/Gold timings, Improved enhance soil/timing, and Rx gain adjustment 1-20. 

Relevant to: GPX 5000