I have a Rincon with stock size bighorns. I weigh 180lb and carry an extra 100lb of gear. Riding is a mix of slow off road pushing through bush to fast speeds on the dirt tracks. Hardly any mud, not much sand either. Currently running 5psi in the front and 6psi in the back as when I’m sitting on the quad it is what "looks right" as in the tyres bulge out slightly where they contact the ground.
While the bighorns seem good, they do also seem soft and pliable, which I guess is why they are flexing out more than I thought they would.

Fwiw, on my old foreman with original bearclaws, I ran them at 4psi and they didnt seem to look as "deflated". Carrying the exact same payload.

So, what does everyone else run?
Also, average temp around here is about 95°f and overnight about 60°f, so not very cold…