The product is mature and stable, definitely. I am one of the many satisfied users of Symantec products.  

The stability is good. It's even better than it used to be, as we'd initiated a lot of new rules.

The solution wasn't too stable. We had issues around the utilization.

Symantec Cyber Security Services is a stable solution that is working fine. It runs in the background at all times.

In terms of stability, this solution is very good.

We have not had any trouble with stability issues.