This is a case where I would have both, if you can afford it. I do have both and at one point I tried to go with just TID, but I keep coming back to having a Tesoro machine for the simplicity, depth, and lightweight package. Like someone mentioned, if you're digging relics you're going to be digging pretty much everything anyway. My approach, when relic hunting, is to check out an area using my TID machine to get an idea that I'm in the right area. If I find something from the right period then I start in with the Tesoro and dig everything in that area. The Tejon is deeper, with minimum/no discrimination than a lot of the TID machines and certainly lighter. If I had to choose between the two I'd take the Tejon, because as you get better with it you'll dig more goodies, but with a TID you'll start to lean to much on the ID capability and while you're learning it, its wrong on deeper targets often enough that you might as well be learning a lightweight, simple machine like the Tejon.