Hi,
It depends much on monitoring configuration and load. In default configuration AVIcode is shipped with server side monitoring imposes about 3 - 5 % of performance overhead.
If you use AVIcode uX (additional component for client-side monitoring) in default configuration this measurement will increase up to ~ 8%. Server side is prerequisite for uX, so this 8 % already includes mentioned 3 - 5 % caused
by server side.
These results were achieved during AVIcode 5.7 testing.
The overhead is usually not so significant, thus we may claim that AVIcode is designed to be used in Production.
Igor Savchenko, VIAcode Consulting LLC (http://www.viacode.com/solutions)