The GPX5000 Fine Gold Timings are very good, I researched VLF vs. PI Detectors for some time and came to the conclusion PI was a better investment for me. It is significantly more money, but well worth it in my opinion. The GPX is easy to operate, excellent technology and only extends it's advantages with time spent utilizing it.
I would do the same again.
It will always depend on your ground/soils, highly mineralized soils is where the GXP will shine, if it is within your budget, I would recommend spending the extra money on what many consider to be the Best PI around.
There are some very good VLF's, the Fisher Gold Bug Pro & the Eureka Gold are very good.
I borrowed a Tesoro Lobo and found it to be an excellent basic VLF.
You have options, choose wisely based upon your budget and needs.
Happy hunting in Utah~!