I am always on the look for any renovation work. Often I find old (for us here in the USA) sidewalk repair where the dedicated narrow area has an abundance of rusty iron nails that were lost at the time of original construction. I also look for 'tear-downs' of older homes, apartment buildings and businesses. Due to loss during the original construction and as a by-product of any renovation through the years and the recent demolition of the structure, iron nails can be found in abundance. Of course, just what I mean by "abundance" might not be what others would perceive as the same.
When I am hunting old racetracks, horse barns and other fairgrounds & arena areas, I plan on encountering an increased amount of smaller animal shoe nails. When I work military encampments and other similar sites where there could have been a lot of crates opened or destroyed (burned), then I anticipate crate-type nails. Near homesteads and especially more modern structures, roofing nails will be in the mix with larger 'construction' nails.
To me, these different types of sites might all have "iron nails," but they might be different sizes (thickness and length) from quite small to large.
But I also hunt a lot of old ghost towns here in the US. Some actually have very little iron debris other than the occasional nail, while others might have a heavy or dense scattering of nails due to buildings that have burned or been destroyed otherwise. Some of the older "towns" were actually camps for mining or prospecting and have more iron than just nails, but the bulk of the older town-sites I hunt are associated with the pioneering of the railroad in the western US. If I had to describe what I consider to be a very tough environment with iron junk, or "amongst iron", I immediately think of the RR ghost towns I work.
So, if you're asking how the X-Terra's handle those types of sites, where you can easily get 6 to 8 or even 10 target hits on a single 4-foot left-to-right sweep, then I will tell you they do pretty darn good! They'll do better with a smaller coil and/or a DD type, I am sure.
"Thanks for the reply Monte,".. You're welcome.
"I would like to know how sensitive the X-Terra 70 is on say a tiny hammered coin, small nugget, thin gold chain."... I have used some of the smaller hammered coins my friends have brought back from the UK and, in our comparisons, the X-Terra's have been very impressive.
I found a nice 10k bracelet that was rather thin. It was a child's bracelet and responded with a very good audio.
Small foils and other difficult targets (for some makes and models) have been sounding off rather well for me so far. The X-T 50 has been very good, and the X-Terra 70 a little better.
"Is it as sensitive as say the XP Goldmaxx or a Tesoro Cibola/Lobo."... The Tesoro Lobo SuperTRAQ used to me a main-use detector for me, and I often hunting with it in the discriminate mode set to just reject the ground signal. It did 'OK'. Of the other Tesoro models, if I was forced to have to choose one to use today, it would be the Vaquero or Eldroado (