25 Gbps isn't all that much. It would be good, but would be below the 40+ Gbps I was getting on the TB5 ring network.
I think where it would show more significant speed up is on the AMD Strix Halo cluster.
Except I haven't been able to get RDMA over Thunderbolt on there to work, so it'd be apples to oranges comparing ConnectX to Thunderbolt on Linux.