SoapUI 4.0.1 slower than 3.6.1

I've noticed an big difference in these two patterns:

Pattern A
1. Invoke a service method --> 20 ms
2. Invoke a service method --> 20 ms

Pattern B
1. Invoke a service method --> 20ms
2. Invoke a script that conditionally reexecutes step 1, one time --> 2 ms
3. (reexecution of step 1) Invoke a service method --> 600 ms (back-end did not take 30x longer!)

It seems "something" connected with the conditional branching adds time which is being tallied to the 2nd invocation of the same service in Pattern B.

Makes looping and sending a continuous stream of sequential requests to a service with no pauses impossible.

Loop method (in groovy script after the first invocation of service)...

if( !context.hasProperty("myCounter1") ){
context.setProperty("myCounter1", 0)
}
def myCounter1 = context.getProperty("myCounter1")
myCounter1 ++
context.setProperty("myCounter1", myCounter1 )
if(myCounter1 < 2) testRunner.gotoStepByName("InvokeService");

Based on comments I guess I need to revert to SoapUI 3.6 to get continuous submission of requests in a loop? Strange.