Sven
Military controllers will always endeavour to hand you over to the next unit if you are recieving a radar service, and as such you have priority over FIS traffic.
If the frequency sounds excessively busy, then FIS tracks will be offloaded first, and the supervising controller will help out the LARS/Zone controller to hand over radar traffic.
If I were you I would sit tight until handed over and only offer to freecall if you are now in conditions where you would be happy to take a FIS.
(and before everyone starts, there are occassions when we freecall RIS's, but its not very often!!!).