RBK23 Tri-Band + 2 Satellites

Alas, vendors describe their WiFi products by adding together the maximum theoretical bandwidth of all of the radios. The Product Data Sheet for the RBK23: https://www.netgear.com/images/datasheet/orbi/RBK23.pdf  says it has three radios, which are theoretically capable of 866 + 866 + 400 = 2,132 mb/sec, which they round off to "AC2200".  Of course, 866 of that is the backhaul radio between the satellites and the router, which users have no access to.  866 is the maximum theoretical bandwidth of the user 5G WiFi signal, and 400 is the maximum theoretical bandwidth of the user 2.4G signal.

A lot of this theoretical bandwidth is taken up with "overhead", and bandwidth dimishes as the signal strength falls off.

So, there is no possible way that a WiFi device connected to a satellite at 5G can consume more than 866mb/sec.  In practice, of course, neither of these links can perform at that rate.

None of this answers your question: "what is the most the Orbi RBK23 can deliver when I have a gigabit internet link?"  I doubt that anyone "knows".  There are several active posts questioning whether any Orbi can fully deliver a gigabit connection.  I know that my RBR50 can deliver 225mb/sec to my Sony smartphone.  (I don't own an RBK23.)

My guess is that the RBK23 is not going to deliver as much bandwidth as the RBK50 product.  And, neither is going to deliver as much bandwidth as the newer "AX" product line.

Sorry to rave on and not answer the question.