Schmid,
I have been really pleased with the FMC of the new version as before I could not finish a flight in 6 months due to the CTDs. That seems to be history now.
I have found no problem with setting up STARS, ILS approaches, and SIDS when at the departure airport. However, the FMC does some odd things when you want to change the runway or approach near the end of the flight. You have to pay very careful attention as to what waypoints it puts in and make sure that the route is correct, waypoint by waypoint. Sometimes the runway is added to the end of the route, sometimes Vectors is added in the middle, sometimes waypoints are doubled up, sometimes the current route gets erased and replaced with the ILS approach, and the altitudes need to be checked too, but it is all fixable very quickly for someone with your knowledge of the FMC. I also am pretty knowledgeble and got caught up by this on an approach when trying to change from Rwy 27 to 18C into EHAM last night. It took me like 3-4 tries to get it right and even then I missed one odd waypoint that I didn't catch until the last minute. It definitely is not what I am used to after flying other aircraft, but, well, that is life, time to get used to something else
However, I have to say that other than a few quirky things, the FMC seems to work pretty well. I wish a few more things were modeled, like ALTN, MENU, calculation of distance to TOD, for example, but I am happy with it. The FMC not calculating CG and giving the required takeoff trim is inexcusable though, really. I have figured this out by now after having taken off a few times with trim values in excess of 6 when it really needs to be 2-3
We are not used to CG values of 40% but...well..now I am.
Happy flying to you.