You might want to go back and look at some of the posts Balinor has written about upgrading. The general concensus is don't do it unless there are features in 4.2 that you NEED. Most of us will be waiting on version 5. We have put up a test version of 4.2 to playaround with getting our design and MODs to work in it. We have no intention of switching unless version 5 falls apart.
For us it was worth doing because of the CCS, which is a joy to work with once you get a grasp on it.
Mike