What do you like best?
It is a 2FA solution with easy management and compatibility with a good selection of vendors. There are integration tools that will let you add 2fa to a number of popular platforms that don't offer it natively. The dashboard is clear and simple. User management is a no brainer, and there are some nice little reports that give you an accounting of activity. There is even an apple watch client app that provides a one touch approval for multi factor logins. The directions for the integrations with third party products are clear enough that we have never had a problem tying them in to the Duo system.
What do you dislike?
Not much. It would be nice if they offered a tier with more security options, such as limiting access by geography or whitelist only ip ranges.
Recommendations to others considering the product
It is extremely simple to get up and running. If you already have products that authenticate using radius or ldap, you are halfway there. The back end service does have occasional and brief outages, which may cause a disruption for very large organizations with a constant flow of traffic, but for our needs, the downtime has been almost imperceptible. For authentication against local resources, you will need to host a proxy server in house to which requests will be forwarded.
What business problems are you solving with the product? What benefits have you realized?
We have been able to add multi factor authentication to several platforms where we did not have it before. The amount of security this adds for the price is absolutely worth it. We are able to better secure anything that authenticates through our active directory.