Recommendations for Cisco OOB console port connectivity at remote sites with cellular access?

I've bookmarked the discussions in the past when people asked for recommendations on which serial console server brands people are using for OOB access to Cisco gear. Opengear seems to get mentioned a lot. For people who manage remote sites and need OOB access to the serial console ports on Cisco routers, switches, firewalls, etc. with cellular connectivity, what are the brands to look at? Is there one company that does cellular (in the US) OOB better than other vendors? Thank you.