If I were forced to reduce my number of detectors to three, it would be very difficult.
At first, I thought I'd keep my TDI, DFX, and Surf PI.
But then I thought about how much I enjoy my XL Pro and Beach Hunter, so maybe keep my DFX, XL Pro, and Beach Hunter, but which BHID, the 950 or 300? Each has it's strengths.
For the monster depth capabilities, I guess I'd have to stick with the TDI and Surf Master PI, which leaves the DFX for those days I am feeling lazy and want to discriminate.
Fortunately, I get to keep all of them.