Now I am confused a bit. Are you thinking about rbsxtg-5hpnd or crs125? Hope the second.
Anyway crs125 is the same like rb2011 just with different switch with more ports. Maybe you do not need them in house. Generally it could be enough, depending on your situation: wall and ceiling materials, other wifi in neighborhood and power and selectivity of your client devices. I would start with one device at place where I need the most connections and if necessary I would add auxiliary ap where the signal is missing.
That seems like sound advice. If I go with the Mikrotik RouterBOARD RB2011UiAS-2HnD-IN, think that might cover a 3,000 square foot home w/ 2 floors and basement? There are only three wireless access points coming around the neighborhood, and the signals seem pretty weak.
FYI, I believe I am getting a free Meraki AP (MR-18) because I joined one of their webinars. So, I can probably use that to scale up in my house if the wireless is not big enough.