WIFI speeds and standards

I have "upgraded" the routers in my house to TP-Link AC1750 units. There are two good things about these:

• I can buy them on Ebay for about $20 each.
• I can run OpenWRT on them.
• They are much better than the Linksys WRT54 units they are replacing.

• How to install OpenWRT

People say that while 5Ghz is faster, it has less range. The fact that 5Ghz has less range can be a plus, it is less likely to interfere with (or be interfered with by) other 5Ghz access points.

I now own 3 of these routers, maybe 4. One is a gateway (with Wifi disabled) and the main distribution point for my home network. This router failed at some point and was replaced. Another is in the guest house, and the last is just now being deployed in my workshop. We have yet another access point (in the kitchen on top of the refrigerator).

The kitchen access point is a TP-Link AP225 which was advertised as a "business solution", but the 5 Ghz speed is "only" 867 Mhz. Maybe. This is confusing given that it is claimed by some literature to support 802.11ac -- but there is a lot of double talk, and a variety of different models with similar numbers yet different features. There may be a more specific AC1350 number or some such that will lead to less ambiguous specifications.