@CharlesM99 

To recommend you optimal for your network configuration, I need to know more about your router and switch.

1. Your router, how many and what speed Ethernet ports it has?

2. What is your switch brand name and model number?

  @Alexandre. 

Thanks for the quick reply. Yes, the router is a Zyxel ax7501, so it has an sfp+ port where the fiber connection comes in from the isp. Then it has a 10Gb ethernet port which feeds the 2.5 Gb switch. The zyxel also has 4x 1gb ethernet ports. Then the switch goes to two other access points currently. I plan to remove the other access points, and disable wifi on the Zyxel router and only use the ex75 pros for wifi. 

The switch is a 2.5Gb switch (QNAP QSW-1105-5T )

I just realized the 10Gb ethernet port on the Zyxel is 10000/1000/100, and not 10g/5g/2.5g/1000/100 so it's probably negotiating to 1gbe anyways. 

  @ZakCT OK thanks for the advice. 

We've been having some issues with reliability in our network, which I'm hoping to address with this upgrade. Are the issues with the xe75 pros causing unstable networks? Like will my room mates complain about not being able connect or being dropped?

  @ZakCT oh man, no that does not sounds like what I am looking for. I am capable of messing with internet settings and playing around with stuff but the room mates want something that just works and works reliably without any issues.

I had setup a Deco X20 system a few years back for my parents and it just works, and works well. Sounds like that reliability did not transfer over to the newer tech unfortunately. 

  @CharlesM99 

You are going to receive competing recommendations, so pick what you like. There is more than one way to solve every task.

You can have that network layout:

This will make sense, because XE75 Pro has one 2.5Gbps port. You can use it to connect Deco to the switch that supports 2.5Gbps.

To do that, you will need to configure Deco mesh to run in Access Point mode.

You Deco mesh setup will be as following:

1. Connect first Deco unit to router with Ethernet cable. Power it on and configure according to the guide that should come with Deco set;

2. Bring remaining Deco units close to Main Deco, do not hardwire them, power them on. They should join Deco mesh automatically in about two minutes. If not, follow this document to add them: How to add an additional unit to your Deco network

3. After you have all Deco units in Deco app as online and healthy, configure Deco mesh to run in Access Point mode: Switching a Deco to Access Point (AP) Mode

4. You can now hardwire Satellite Decos to the switch.

For Deco mesh to work that way, both Zyxel ax7501 and switch (QNAP QSW-1105-5T) must support Deco Ethernet backhaul protocol. ISP routers usually do, but with switches it depends. The topic of Ethernet backhaul is discussed here: General questions about Ethernet Backhaul feature on your Deco

For optimal performance, your switch should negotiate 2.5Gbps with Zyxel ax7501. If Ethernet port on the Zyxel is indeed 10000/1000/100, you are limited by 1Gbps, as you correctly assume.

At some point, you may decide to replace that switch to unlock Deco mesh performance. Choose 10g/2.5g/1000/100 switch, you might have to pay more for it but it'll utilize 10Gbps link to Zyxel and 2.5Gbps links to Deco units. TP-Link switches are usually safe bet, if you can find one with these specs. Unmanaged switches are recommended over managed.

  @CharlesM99 

One more thing: because you already ordered XE75s, and you have experience with Deco mesh, you should try them. This forum is frequented by people who have issues with their Deco mesh, and they sometimes assume problems they have everyone will have. There is not very many people coming here to say "Thank you, TP-Link, for an excellent product with which I have no issues."

Keep that in consideration. As they say, YMMV.