We have been using it for six to eight years. We have been through two iterations of the Exinda appliance, because we upgraded it at one point and just kept it up. The last major upgrade was four or five years ago.

6+ years

I have been using Exinda for somewhere in the vicinity of five to six years.

We've been using Exinda for over five years.

I have been using Exinda for almost five years.

I have been using Exinda for around five years at my current company but I have around 10 years of overall experience with it. 

I have been using Exinda for six months.