I've been using it for about five years.

I am working with RHEV currently.

We have been working with this product for around three years.

I have been using RHEV for more than eight years.

I have been working with Red Hat Enterprise Virtualization (RHEV) for five years.

I've used the solution for eight to nine years. 

I have been using RHEV for at most a couple of years now.

I am not a system admin and not into the infrastructure. My role is mostly on solution architecture infrastructure so I don't do hands-on on these technologies, but I have my basic lab set up where I play around with them because my job is to provide solutions and advice for customers. That's how I am engaged with it.

I have been using RHEV for approximately four years.

I used the product for 10 years. 

We have been using the solution for half a year.

I've been using the solution for about two years now.

I have used it for a couple of years.

I have been using this solution for a few months.

I have been working with Red Hat Virtualization for between 10 and 15 years.  

We've been dealing with the solution for about 15 years now.

We're just starting to use the solution. We've been using it for less than a month.

I have been using this solution for more than three years.

We have been using the solution has been for about five or six years now.

I have been using RHEV for about five months.

I have been using this solution since the very beginning — about eight or nine years.