We rode Nevados de Chillan the first week of August. It was dumping the day we arrived and through the night so we had 2 great powder days. Even the groomers were soft and fluffy, but if you're willing to step off and hike for 20 minutes in any direction this is where Chillan shines. Deep, powdery bowls, cornices and wind lips and untracked pow everywhere.
A few locals took me for a back country tour and it was as beautiful and challenging as anything I've ever seen. I highly recommend this place for your off piste delight.
On the other hand, we did get stuck on a lift that malfunctioned for 15 or so freezing minutes and the Don Otto is long and slow.
Still, I cannot help but sing the praises of this place. We may just have been lucky as I hear there hasn't been much snow this year, but on a powder day its world class.