Java layout managers are a total pig - I can't tell you the hours I've wasted fiddling, trying to get my GUIs to look just right.

Of course, things might have gone more smoothly if I knew what I was doing. ;-)

In the end, I ended up writing my own layout manager. But I don't think that I'd have had to had this been available at the time - RelativeLayout, a Constraint-Based Layout Manager.