First, in answer to the discussion about the Omega not responding to ground when bobbed in the Disc. mode. I did the same comparison with the Omega as I have done with most of the detectors I get my hands on to own or just evaluate, and I do not know which video you are referring to. I do know, however, that when I used three Omegas, since March of 2010, I used some very mineralized ground as well as some rocks I use in my seminars. One hand-sized rock produces a Ground Phase reading on the G2 at about 89.8 and I ran the Omega manual GB to each extreme and couldn't get a response ether way.
Using the Teknetics G2 and the same rock, I just double checked and found that once I GB'ed to the rock, I could increase the GB to the maximum setting, switch to the Disc. mode, and not get a response. The G2, depending on how I held the rock, the GB balanced at 89.7 to 99.0. When I reduced the GB manually to 71, then switched into the Discriminate mode, the G2 was responsive as the rock was bobbed toward-and-away from the coil. Reducing the GB setting even lower made the rock very responsive in the Disc. mode.
That being clarified from my testing, let me add that you are correct that some makes and models DO respond to extreme GB settings in the motion Discriminate mode. With some models, a higher-than-proper GB might produce a positive response in the Disc. mode if the coil is bobbed toward the ground, whereas some models might audibly respond with an uplift of the coil away from the ground when the GB setting is too negative.
It is all about how each particular model is designed. Most Tesoro's, for example, with not respond to a big silver dollar in the Disc. mode if the GB is adjusted for the maximum GB position. It is also possible to design a mode where the Disc. mode ahs a preset GB, one where it references directly from the All Metal mode GB, and it is also possible to design a detector so the Discriminate mode GB adjustment range is limited. I believe this might be the case with the Omega's design.
As for personal opinions as to the performance differences between the Omega and Euro-Tek Pro, the Euro-Tek Pro was designed as a simple to use model and that would be a popular model for a lot of the European relic hunters. It serves similarly here in the USA as a simple-to-use detector. I find the performance to be somewhat similar to the also fixed GB Delta model, allowing that the Euro-Tek maybe does provide better Discrimination adjustment.
My pick of the two, however, favors the Omega for several reasons. One, it DOES have manual GB. It does have an All Metal search mode. It provides us with four different Tone ID selections. There is more ground make-up information, such as Fe3O4 and Ground Phase readings. Does the Omega sometimes have a little more EMI? Yes, but not all the time and I mostly hunted with the Sensitivity set at '99', reducing it when needed. I'd rather be able to reduce a detector if the setting is too high, rather than have a model that can't adjust high enough to get to the point of instability.
Better still, I prefer the Omega because Dave Johnson is proud of it and his involvement in its design, whereas he didn't design the Euro-Tek. That was done by a couple of other guys down there. When they announced the Euro-Tek's release and had the flyers out, I called and talked with Dave to ask if the Euro-Tek Pro adjusted to a true 'Zero' Disc. setting. He said he didn't think so, and he wasn't involved with its design. He had other comments but this will suffice. I just know that it's OK for the price point it is at, but the Omega is a better all-purpose, more functional model.
Monte