I agree with mparadis.
The above noted it becomes difficult sometimes as also stated above relating to RF and house infrastructure.
Personally here see a combo "do what" Verizon Actiontech M1424WR as an easy solution of a combination modem, router, wireless access point, switch and firewall. This is an easy peasey means of being able to service one box by your ISP. It is one box to manage via an easy to read GUI interface.
The trending is to lock the ISP's box down which really is a good thing for the ISP and for the client's own protection.
Here and there I have cable and fiber ISP connectivity.
I am using a cable modem / PFSense firewall (plus redundancy ISP connections) and separate managed switches and wireless access points.
IE: ISP ==> ISP Modem ==> Firewall = = > managed network switches and autonomous wireless access points. (personally this gives me granular control).
The combination automation, wireless, router, switch and touchscreen Almond 2015 fits in nicely as an addendum to already configured infrastructure.
You have to make it work though because you have a quandary of hardware that you want to make work together
1 - The Almond 2015 device is a combination automation LCD touchscreen, automation software (firmware), wireless access point, wireless repeater, switch and router. It was/is designed to be a multiple function device. The + (plus) features of the Almond 1015 is the LCD screen and automation pieces that do not exist today with any company that I know of.
2 - The ISP's combination modem, wireless access point, switch, router and firewall is just that and nothing else. There is no automation nor does the Actiontech device have an LCD screen built in.
I know it seems like a lot but really is not.
The wireless access point placement is most important such that I utilize POE powered access points. There are sort of innocuously positioned in the home not to see in a physical sense but rather only wirelessly.
I have done similar with the Verizon fiber connection box but a bit different leaving the Verizon box in place for the television STB's, disabling and removing the wireless antennas and bridging one network port for my stuff which is totally separate. It is split primarily as two networks; one for the television stuff and one for my personal internet stuff. The personal internet stuff is further subdivided into wired and wireless autonomously talking to the same Verizon box. I am not writing here that this is the right way to do this but rather what I have done.
The historical issues though mostly have related to wireless footprints of these combo devices; well and the fact that they are combination doo all type of devices.
If possible you may want to relocate the ISP provided Actiontech combination device maybe on the second floor such that the wireless repeater if needed would be on the first floor and the Almond 2015 would remain on the 3rd floor. That said if there are no wires and wireless only dependencies then you really only have the choice as primarily suggested.