I bought the TDI Pro predominately for deep hoard/relic hunting here in the UK,so i also geared up with a selection of larger than stock size coils,and this does work very well and of course the occasional use on the beach and a couple of highly mineralized inland sites that a normal VLF machines just wont work on.
The TDI does exactly as i wanted it for deep work,but when using it with smaller coils ie 7.5DF,MJ 9x5 folded mono and stock coils when i tried coin shooting and after say 6 months of trying,i came too the conclusion that although its possible it was not the best machine for the job,it was not a enjoyable experiance altering the setting to run smoothly and then decided that after making headway i would just carry on using it for hoard hunting and beach work,this excels at.
So basically for everyday use or coin shooting the VLF option was so much easier and also less stressful,the TDI does have uses and these days i just use the raw power and run it in straight PI mode,this then does everything that i want and basically what it is best suited for.
If i want real depth on say single coins or large deep items with real discrimination then i bring out the Nexus SE too play,that not only gives me the same depth as the TDI and possibly even deeper when using the dual 9'' coil but with real discrimination then its a no brainer which machine to use.
As Steve often quotes 'Use a VLF when you can and a PI when you must' i have come to the exact same conclusion,but only after using the TDI for detecting scenarios it was not designed for,it is a very adaptable machine but does have some limitations like any detector,so once you find out its limits or what it was not designed for then use it accordingly.But when you do use it for what it was designed for then its a pleasure to use.
Of course we all use a machine differently and i dont nugget hunt as i live in the UK,but it is the right tool for the job when hoard hunting in pasture land,then all it takes is one decent find which could pay for its keep many times over.