different search coil sizes and types can also perform differently from one model to another.
You asked in the subject heading about the Tejón, and having owned and used that model, in the past, and working with others who have/had a Tejón for the places I mostly search ,which are heavily littered with nails and other small ferrous debris, then I prefer Tesoro's search coils. To be more specific, since I am mainly hunting in and around terribly littered sites, I prefer Tesoro's Concentric search coils over any Double-D coil, whether offered by Tesoro or an aftermarket supplier, and I have compared many of them, both types and a variety of sizes, on several Tejón's.
You didn't specify what applications they would be for, and that could make a difference. Having said that, I am a fan of several Tesoro models and all are equipped with a 6" or 7" Concentric search coil. I only have one DD coil for the Vaquero and that is the 8X11 RSD that came standard with my black-version unit.
I don't like the Tejón so I can't answer based on immediate comparison, but for the last two years working with others who have/had that model and an assortment of search coils, the Tesoro Concentric coils out-performed Tesoro and after-market DD coils in several Relic Hunting sites with dense iron debris.
Just my opinion for the type of sites I like to hunt.
Monte