I made a comment on the thread from Steve H., survey about metal detectors.
When you toss out the "price tag" I would rather find a Gram nugget at depth, missed by VLF's, then a Grainer missed by a PI and picked up with a high freq. VLF. Overall, the PI's for the most part will gain much more in weight (nuggets at depth, small and large) over a VLF in my opinion over time.
If you notice, I mentioned "in my opinion" I believe someone willing to spend the time and effort would benefit more from a good PI working old goldfields than a VLF. I have many reason why I believe this and we mentioned we are not included the price of the metal detector. We are talking technology and performance this time.
In the quote above, I talked about how I would rather miss a dink than a larger chunk at depth.
Trust me, I have toggled back in forth from a Fisher Goldbug 2 and PI, owning both most of the time. I'm pretty convinced with the new PI's and GPX 7000, that I'm not missing that many small nuggets. The ones I'm missing don't make it economic enough in a day to pick them up than continue in hopes of picking up another single piece that might make a dozen of those small ones.
Sometimes it comes down to economics & time in the field (productivity). I can either crawl around on the bedrock and snipe 20 small ones in a day for "X" about of grains or grams, or cover more ground in hopes of larger pieces. I have always had better success in the second, moving on, trying to find another deeper one or covering more ground.
That all being said, we go back to the original question I have. I think if you're working old goldfields, a person would have better success with a good PI vs. a VLF overall.
I'm saying this from 20+ years of swinging a metal detector across the US and Mexico. I'm also saying this from watching the various gold forums the last 10 years and seeing what guys are finding. We can also toss the survey Steve just conducted on metal detectors.
For example, if you have watched a handful of guys (probably more like 100's) visit the known goldfield of Rye Patch, Nevada, that place has been worked to depth. It's a huge goldfield, hundreds of thousands of gold nuggets have been found in region. Despite that, the area still produces handfuls of nuggets from guys working that goldfield.
Most are using PI's, revisiting known nugget patches, dozen scrapes and other workings to find gold at depth. The SDC's (newer waterproof PI from Minelab) has done an amazing job at Rye Patch, kind of like a GB2 PI unit.
I still remember visiting one of the scraps over 10 years ago, the guys that showed me said it has been killed. It was the size of a football field, if not larger. He pretty told me good luck, the Goldbugs have killed it. Within just an hour's time with the latest and greatest PI, I had over a dozen "chevron" nuggets for like 4 Grams of gold. All the nuggets were just a few inches beyond VLF detection range.
These are just some of my personal views and opinions, but would love to hear what others have to say about the subject.
I guess we can also add, what is "personal success" or being productive. Some are just happy with being in the outdoors, others love to find a nugget or a combination of them both!