P.S. - i have now scrolled over all images in the middle grid of LR5 and organized and sycronized and did a sycronization of metadata. the new Lightroom_5_catalog previews.Irdata has grown to 10GB. the original one under LR4 iw approx 139GB.
is i possible that LR5 is just more efficient in storage or do i have something missing?