Anyone deployed SD-WAN to replace MPLS circuits?

I am interested in this as a way to reduce MPLS costs and also provide some excellent QoS for regular WAN traffic to specific cloud services.

I also like the way that I heard it can balance traffic between multiple WAN VPN links to sites.

I currently have most sites running with site to site VPN and a few MPLS circuits at some of my bigger sites and have static route failover set up to pump traffic over the VPN if the MPLS goes down.

I am interested in your experience and getting an idea in the cost for hardware required to set it up and how that compares to the ongoing costs of MPLS.