We tried both at work and thet were more or less equivalent but proxmox appears to have more momentum behind it. Also distributed storage in proxmox is based on ceph while xcpng use the obscure xostor

I can't speak for pros and cons with XCP-Ng. I've been meaning to try out XCP-ng. But feel like there just isn't a large enough community support around it yet. At least not like Proxmox, which has seen a surge in usage and popularity after the Broadcom fiasco.

Maybe a surge of newcomers, but the community was strong before and irrespective of the fiasco.