I can vouch for the grip on Le Chameau - best of any I've had, I think. I did a lot of walking on Exmoor in my Le Chameaux. Oh, and horse-riding too.
I cannot vouch for how the rubber stands up to cattle urine and dung, though, as my Le Chameaux had been ruined by someone wearing them for rowing (stretching them, and leaving them damp in a bag
) before I got to the point of having any cattle.
I'd got mine about half price at a summer fair, or would probably never have tried them. I wanted wellies with a good enough heel for riding, so I could have waterproof feet and ankles if needing to dismount in muddy conditions.
Having now had them, I would buy them again if I was sure the cattle urine wouldn't rot the rubber. So am interested to see the responses to your query.