I have an Edge-Core AS7326-56X running SONiC. The hardware is quite nice, but SONiC is such a moving target that it's hard to really recommend it at the moment. It's probably fine if you're doing "traditional" datacenter things like a BGP-based spine-and-leaf setup, but weird stuff like VLANS with STP doesn't actually work (although it should soonish).
Also, I can't get it to talk to CX4 or CX5 cards at 100 Gbps right now. I mostly blame Mellanox's weird VPI autodetect thing. I'm waiting for fs.com to send me more DAC cables before I really try debugging.