I am a bit late to the party with Groups but am now using it in earnest. I am finding it difficult to get used to the fact that clicking a node in a group selects the group instead of selecting the node. Personally I would much prefer if I had to click the boundary to select the group. Am I missing something?
You are not missing anything. It behaves in the same way grouping does in many other applications like PowerPoint.
Getting the user interaction right with groups is obviously a key element. As more people use them, I will be interested in the feedback to see if we've got it right, or - as you suggest - we should look at alternatives.
It doesn't seem right that clicking a node selects the group, but clicking a wire doesn't, and in fact clicking a wire or adding a wire in a group deselects the group.
However, nobody else seems bothered about the whole thing, which I find rather surprising.