Internally, the Orbi units each have a 2.4GHz radio rated at 600Mbits/sec and a 5GHz radio with a theoretical maximum transfer rate of 1,200Mbits/sec. That’s a decent chunk of bandwidth but, since there’s no third radio, this has to be shared between client and backhaul traffic.
As with all Wi-Fi 6 gear, the Orbi RBK352 is backward compatible with Wi-Fi 5 (802.11ac) clients but it won’t interoperate with Wi-Fi 5 Orbi units. It is technically possible to mix and match RBK352 nodes with satellites from an RBK752 or RBK852 kit, but the performance limitations of the RBK352 will still apply to client devices connected to it.