Hi, new user here looking into setting up a basic home network using Mikrotik gear. I only have basic knowledge of networking so don't be surprised if I say something silly. I'm currently using just my ISP-supplied wireless router with built-in ONT for a 300 Mbit/s. The router is located in the boiler room of the ground floor of a 150m2 three-storey terraced house. The longest distance within the entire property is about 16.2 metres (between diagonally opposite corners on the top and ground floors), and about 12 metres on any single floor. Floors are made of reinforced concrete and all walls within the property are made of bricks (load-bearing walls, which are made of concrete, are all on the perimeter so they wouldn't be in the way of the wireless signal). Using the 2.4 GHz band of my ISP-supplied wireless router, I'm getting 28 Mbit/s download and 8 Mbit/s upload speed at the furthest point on the furthest point possible on the top floor. The 5 GHz band is worthless on the top floor. Things improve on the 1st floor as it's closer to the router. I couldn't find any details about this router but I read from an unofficial source that it features 2 dBi antennas (could be wrong though).
I need some guidance:
1. Since all bandwidth-hungry devices are going to be on the ground and top floors, my initial plan was to run Ethernet cable up the stairwell to the top floor and connect a PoE capable AP, and have another AP one on the ground floor (probably the ISP wireless router). However, I've seen some attractive Mikrotik products like the hAP ac³ featuring high gain antennas and very competitively priced, would a single one of these provide adequate coverage to the entire property?
2. Which is better in terms of coverage (going through walls etc), 4 dBi @ 2.4 GHz or 5.5 dBi @ 5 GHz? I'm specifically comparing the RB2011UiAS-2HnD-IN and the hAP ac³. This matters because not all devices on my network are 5 GHz capable.
3. Looking through the various products, many feature 300 Mbit/s wireless but 10/100 Ethernet, so I'm confused, how does that work out when the wired interface data rate if slower than the wireless one it supplies? Shouldn't wired ≥ wireless?
4. My home network is going to be fairly basic in terms of configuration and ATM I don't intend on exploring the depths of the RouterOS rabbit hole at this point so, if I went with the two AP solution, would there be any significant advantage to replacing the ISP wireless router with a Mikrotik one or would I be better off just connecting APs directly to the ISP router ports with a PoE injector where required?
Thanks in advance!