For anybody starting, the miniatures in the 2nd edition starter box are noticeable smaller than the rest of the miniatures.
It's especially annoying with the marines, cause the weapons are also smaller. It's easily fixable if you have some spar weapons, for example from the multipart marines, to switch with.
For the preds and aliens it's not that much of a problem. They could simply be younger and not full sized yet.
I thought it would be an interesting observation for people who are very concerned with the scale of their miniatures.