Di3 is super quiet but it's not as deep as Di2. Iron separation is the same, still good at picking up tiny targets. I just came back from a hunt around my local lake. Old houses bulldozed their to build the lake, anyways I must have dug 20 lead split shot small ones. I used both Di2 and Di3 Di3 mode you must crank the sensitivity up to 85 to 90 to get close to Di2 depth. But if you think about it, where you want depth you only need two tones. where you need three tones is Iron infested sites. I get tired of looking down at the VDI numbers and just want to dig the high tones on a trashy site. I don't run a real high sensitivity in trashy areas it tends to make the bad sound good so I like it the way it is. Both Di2 and Di3 have their own uses for me, if you want to go deeper in Di3 just crank up the sensitivity to 99 and go. Cog mod is a different animal, the recovery speed is way slow I'm sure it's that way for a reason, and probably performs much better in the wet sand like it was designed for.