How A/B testing affects performance

Hi, 

We are currently investigating some performance issues for a client, and it seems like the issues only appears once one or more A/B tests are running on the site.

When we set up A/B tests we get a lot of the following exceptions in the log files:

System.InvalidOperationException: ValueFactory attempted to access the Value property of this instance.
   at System.Lazy`1.CreateValue()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Lazy`1.get_Value()
   at EPiServer.Marketing.Testing.Web.TestHandler.EvaluateKpis(Object sender, EventArgs e)

When checking the performance issues in detail, we have also a few database queries that use up to 10-11 seconds to complete when there's heavy load on the site. These queries are queries that involves tblABTest, tblABVariant, tblABKeyValueResult, tblKeyConversionResult, tblABKeyFinancialResult and tblABKeyPerformanceIndicator tables. 

In sum this leads me to believe that there are some performance challenges with the EPiServer A/B testing module. 

Has anyone else seen this?