How do I narrow the list if several Comset routers all look similar on paper?

Start by removing the models that do not fit the site conditions. Ask what network is available, whether the installation is fixed or mobile, how many LAN ports are needed, whether Wi-Fi matters, whether dual SIM or failover is required, and whether serial, GPIO, GPS or remote management features are part of the job. Once those basics are clear, the list usually becomes much shorter.

The mistake is to compare every specification line at once. Comset is usually most helpful when the customer describes the application and constraints, because that turns the model shortlist into a practical recommendation rather than a spreadsheet headache.