Its very rare that i use the TID screen,the Deus is basically a audio machine and if it gives a decent signal in full tones or the settings that i use in version 2 then it has too come out,never ever use the notch facility,its mainly you folks across the pond that use that,i want to hear every target in the ground,the TID is not the most reliable feature on any detector and once you start going over say the 8'' depth range then audio is far more reliable at greater depth.
Me personally the most important indicator on the screen is the top right hand one the GB,that i use far more than the TID,when using the actual GB figure on pasture or deep ploughed and rolled fields if the GB stays steady then drops or increases dramatically,this could be telling you that some form of occupation has been in the area like say fires,furnaces,human activity and then i slow down to a snails crawl and then map the area accordingly.Those are the sites that possibly could have the decent find and those are the ones that i am after.
My personal opinion is that if you notch things out,you stand a very good chance that you will miss targets,i guess across the pond most of the targets that you hunt are of a universal type and i guess that is why notch is used more for notching out certain low value coins etc.But in the UK we dont tend to even notch or discriminate out foil as then you would start missing our main targets that we are after the 'silver hammered coinage' these are not all the same silver content or size,so if we use notch or higher discrimination then we 'will' miss these silver coins.
Also some of our gold coins and other older gold targets come in just slightly above iron and once again if you are too heavy with the discrimination or even notch out iron then you will also miss these gold targets as well,early celtic gold and most gold coinage and jewellery can vary gold content wise as no standard of gold content was in place until 100s or even thousands of years after being used.
For me i prefer to use as little discrimination as possible and certainly not notching anything out,its a metal detector after all,let the audio of the Deus tell you then make that final 'dig/no dig decision' but for me i dont trust a screen to make that decison solely,my ears are far better at making that decision than any screen.