@Meraki_noob we run wireless phones and their requirements are much greater than other devices. As an example, a maximum of 10 devices per radio is recommended, meaning that on a single AP, the radio serving the frequency that you use (5GHz or 2.4) must not have more than 10 clients in total, not per SSID.
For Cisco wireless phones, 5GHz is recommended and power must not be set too high (over 17) as the phone can only transmit at a certain level meaning that if you go over that, you will end up with one way traffic where the phone can see transmissions from the AP, but the AP will not see the replies from the phone.
We have 5GHz for phones, dual band for occasional corporate laptops and fixed corporate devices where we know there aren't too many, 2.4 GHz for public and customer devices and 2.4 GHz for supplier devices.
This means that we can ensure the 5GHz radios on the APs don't go over 10 devices.
Another aspect to remember is that when a phone is leaving an AP radio's coverage, there should be two others it can roam to, i.e. don't just string the APs out in a line down a corridor.
