I wondered when someone would ask about the 2-hour timeframe! First off, let me say that sweep speed is relative. What may seem fast to one person is probably not to another. How you determine the "speed" of what your sweep is will probably be in comparison to the last detector you owned. If you are coming from a Sovereign, Explorer or even an MXT, the X-Terra will seem fast. If you are coming from and XLT or XLPro, you will want to slow down with the X-Terra.
The guy I mentioned is probably as much of a diehard detectorist as I am. By that I mean that he is willing to use what ever detector/coil combination it takes for a particular site. His point (and mine) is that by design, metal detectors perform better with the right sweep speed. Our job (yours and mine) is to find out what that speed is for the detector/coil combination for the site we are hunting. Frankly, I don't have the patience to hunt as slowly as he does. I've always been of the mindset that I could find more, in a given period of time, by covering more ground. That is why, when I am out in a wide open space with little or no trash, I'd likely use my Advantage. It responds well to an extremely fast sweep speed and minimum trash doesn't warrant TID. With the Advantage, the faster you sweep it the deeper it hunts. (to a certain degree). On the other hand, I'll chose the X-Terra when I am hunting an open area with intermittent trash, (a couple targets per sweep) as I benefit from having notch discrimination and TID. I can still sweep it nearly as fast as the Advantage. But when I hit a target, slowing it down while Xing over it will give me much more information. Now, if I were going to hunt a park or area that is super-congested with modern trash, (6 or 8 targets per sweep), I'd not hesitate to take my X-Terra in there with the 6-inch coil. It would be an excellent choice for picking out keepers from most of the trash. But, after I had covered the area left and right, up and down, and cross-cornered, I'd likely retrace my steps with my Explorer and the SunRay X-5 coil. The X-Terra separates targets very well. But I have to maintain a moderate sweep speed to make those targets ring out. If I am in an area with layered targets, a moderately fast sweep speed might not allow me to hear the audio response of those good targets laying adjacent to the trash. The Explorer responds best to a slower sweep speed and will allow me to work the coil in and around specific targets. Especially the small Sunray coil. The separation characteristics of the X-5 are amazing when working the coil with slow sweep speeds.
I think of the detector/coil combination as being a paint brush. When I am using the X-Terra, it is like painting a house. My objective is to pass the coil over every inch of the surface and overlap as needed. Just like I would want to make sure paint is applied to every piece of siding and trim. With the Explorer, it is more like I'm painting a landscape or a portrait. I'm not just waving the brush across the canvas. I have to spend more time on detail and make sure that the "brush strokes" are smooth and blend together. Not just overlapped. I am able to do that by using a smaller brush (X-5) and a more refined (slower) stroke. The key is to chose the right tool for the job and know how to use each tool.
Hopefully this analogy makes some sense and helps explain how I view the differences in sweep speed. HH Randy