I use Mikrotik routers for access points (APs), for firewalls, and for routers. I no longer use Cisco, Sonicwall, or whatever AP is hot at the moment. It is all done with the Mikrotik platform.
Mikrotik is a company whose corporate office is in Latvia. They have little market share in North America, but are very popular over much of the rest of the world. They have an extensive product line but I am only going to describe a single model that is useful in a small library, the Mikrotik 433AH with radio card and antenna.
Before I do though, I'll point out the down side. They are hard to learn and configure. You must be very familiar with TCP/IP to configure one. With that out of the way, I'll get to the upside.
This router is cheap. If your were to get a comparable Cisco device, you would spend multiple thousands of dollars. This is less than $300, sometimes closer to $200. It costs less to get a backup Mikrotik device to keep as a spare than the 1 year service contract you would spend with Cisco. Not that Cisco is the only alternative, but the features for the cost is unusual.
It is feature rich. This one device has three routable ports and can have 2 radios in it. Thus, in a small library, one port connects to the ISP, one to the public network, one to the staff network, and a radio card for the hotspot. This provides for segregation of the libraries' PCs.
I often use these as library hotspot APs. I require users to logon, but the logon is simply "patron" with no password. This is easy to inform the public about, and this technique can give me stats on the number of logons to the hotspot, a number our board likes to see. The hotspot can also be scheduled to turn off and on. I get better coverage than I did with Linksys, Netgear, Sonicwall, or Dlink APs, using the low end antenna.
I presently have about a dozen installed in various libraries and, for the past year, not a one has had to be rebooted to correct a problem. But I have been using these for about 2 years. I wasn't using the firewall correctly for the first year and it seemed like I had to reboot them about once a month. Since I figured out the firewall issue, they just sit and hum.
The feature that first attracted me to the 433AH are the 3 routable RJ45 ports and the separate radio port. It is very easy to segregate traffic with this device. One problem small libraries have is that public users will soak up all the library's bandwidth downloading movies and such. The Mikrotik can limit the bandwidth through a port, so you can allow the hotspot users only 2 Mbps as a group, or you can limit bandwidth by IP address, allowing each public PC no more than512Kbps.
I could go on, but maybe I should stop here. If you want to learn more and think you have sufficient tech support to manage one of these, drop me an email at email@example.com. I can help get you started. It will be fun. At least for me.