I did a bunch of testing some time ago comparing them, and they were less different than I thought they would be, and the CineD and Natural seemed to have the same latitude. I'm not sure if somewhere along the line I got confused between Natural and Standard though, so that might be something to test.
Years on, the conclusion I've come to about colour profiles is that if you're going to colour grade in post with any kind of sophistication (and now with the Film Look Creator tool and Resolve colour management we have incredibly sophisticated tools) then it probably doesn't matter which profile you use.
If I was limited to basic tools then I might just use CineD and be done with it.
It's just preference really.
The vND I'm using is the "K&F Concept 58mm True Color Variable ND2-32 (1-5 Stops) ND Lens Filter". They offer one with a larger range, but it isn't the True Colour one so I suspect it has more colour shifts. I've been really happy with it and my tests didn't show any colour shifts. I asked some professional cinematographers for advice and they said this was the cheapest one they'd recommend, so I suspect this is entry level. The NiSi ones were also recommended, but they're significantly more expensive.
As always, do your own research, but if you're curious I might have my tests somewhere.