A good quality home or small office 4G modem is one that is fast, easy to use, has great WiFi coverage, and looks the part.
The Mobile Network Operator will often provide a 4G-5G modem as part of a package when signing up for a service. They are usually one of two types:
Mobile Broadband Hotspot: This is a small “pocket WiFi” device which is battery powered and provides good WiFi coverage within a room or two. Hotspots are great for short term use or while travelling, but have a reputation for issues when used long term. Their packets-per-second processing is usually quite limited making them more suitable for connecting only a couple of devices. With hotspot functionality on just about every mobile phone there’s also not a lot to offer beyond what an ordinary smartphone can do.
Mobile Broadband Router: These devices look a lot like a conventional household modem. They sit neatly on a desk, window sill, or bookshelf and provide WiFi coverage throughout an ordinary sized home. Because of their less compact size they usually have a more equipped mainboard and larger internal antennas which makes them more sensitive and able to provide faster speeds compared to hotspot devices. Likewise the internal WiFi antennas are better positioned and provide more consistent coverage throughout the house.
If you haven’t upgraded your 4G modem in a while, the latest range of cellular modems are LTE-Advanced Pro or 5G devices. Pay attention to the Device Category which determines how quick the device is – the latest devices are Cat-19, 20, 22, and 24, and can deliver data speeds well beyond 1 Gbps. For WiFi performance keep an eye on the WiFi protocol. The latest modems are either 802.11ac Wave 2, or WiFi-6 802.11ax.