Doc,
You hit the nail on the head when you stated "a better fit for how I think and how I wish to hunt". Only you know.
And I am sure you take in all considerations, including the fact that near water, a water proof unit is the only unit that gives you total piece of mind when you think about it being dropped.
No matter how great the detector is, near or in water without being waterproof, you always have to be cautious.
I love my new GQ SS PI, but I am always wary of where I am in the wet sand/suds because it's not totally waterproof.
Salt water and salt air conditions can wreak havoc on electronics, so I am very careful when using my DFX, X5 or GQ on the beach.
However, it's wheels blazing and no worries with my BHID, Excal and Wader. I just wash em down when I get home.
Still, I love using them all.
I was thinking of trying out the TDI too, and there is a great used unit for sale on the forum, but I have to sell a machine or two to do it since economic conditions won't allow me to just buy another one. And...it's not water proof.