Specs vs real world ...

Orbi CBK752 [CBR750+RBS750]

Spec sheet says: https://www.netgear.com/media/CBK752_tcm148-92067.pdf

Technical Specifications
• Orbi AX4200 DOCSIS® 3.1 Cable Modem Router and AX4200 Satellite
(600 + 1200 + 2400Mbps)†

That's 600Mbps on the 2.4G channels, 1.2Gbps on the 5G channels, and 2.4G for Backhaul on the second 5G channels.

Here's what the CBK752 really does ...

We can forgive the 286M on 2.4G due to congestion and the AP being neighbor friendly... the open 5G is what it should be at 1.2G, but the backhaul is half what it is spec'd for. The 2.4Gbps is specifically why I purchased this model: the slave connects up to my main LAN (sort of a makeshift bridge) and I wanted to ensure I can move data at 1GbE port speeds.