The features of Tenable Nessus that I have found most valuable are its reliability and its ability to collate a dependable output, where we are able to get the same vulnerability when we test manually. The output is quite reliable.
In terms of what could be improved, I would say its reporting portion.
Additionally, we have the on-prem version, but sometimes we want to have an on-cloud deployment as well for certain projects, although not so many. The people who used it on cloud didn't find it as good as the version they were using on-prem. Overall, the cloud version could be improved.
I have been using Tenable Nessus for about three years now. We are currently using the latest version.
In terms of stability, recently we are seeing many updates coming in and we are finding that the updating model with its latest releases may be a little buggy. So sometimes deployment may take a couple of times and Nessus takes its own time for updating, thereby delaying the deployment time. Of late is, we are seeing updates coming in very frequently. So when we deploy it, it just updates again and again and that almost doubles the time.
Tenable Nessus is scalable. That's not an issue.
We did reach out to technical support. I think it was just once, but it took them a long time to respond. Maybe it was case specific, but they took a few days to get back to us and we didn't expect that. Now they've completely changed the model to email support, so we send the email and we'll have to wait until the guys answer us back.
The initial setup on-prem and on-cloud did not have any issues. It just took a couple of hours.
On a scale of one to ten, I would give Tenable Nessus an eight.
What happens is Nessus keeps on updating and this becomes a showstopper. We are unable to proceed with the vulnerability scans or testing if we do not update to the latest available patch. We can understand the risk if it's maybe one version earlier, meaning, we understand something was updated with XYZ patch but there should be something which gives us an option so that not all of our deployments need to have the latest patch. This would save the deployment time because of frequent updates.
I would recommend Tenable Nessus. Especially the commercial model. We operate in small and medium enterprises and for them, Nessus is becoming expensive. Because of this I may not buy Nessus this year and I might switch to Qualys, for example. Overall, Tenable Nessus is not so price pocket friendly for small and medium users.