Can anyone recommend a 48 port rack-mountable NAT Switch/Router?

I appreciate the Mikrotek links. A few years ago, layer 3 switching was red-hot, and you had your pick of Juniper, Netgear, Cisco/Linksys/Meraki, Ubiquiti, HP. I tried Mikrotek but their web and command interface was just terrible. Then it all just disappeared and the big players wanted to separate switching and routing again.

Ubiquiti’s still a solid player, and I think they’re impossible to beat if you also need PoE, but I will pick up a new Mikrotek for my next project and see how it performs.