As mentioned earlier in this thread, I would also love to see a fix for the unequal bag icon size. It's awful looking and really the only complaint about Bartender4 I have.
As for the comment regarding the authors inability to fix it as it is the result of a design change on Blizzards half, look at an add-on called Dominos. They have done the bag bar (which includes the key ring) very well. In the words of Picasso, good artists copy, great artists steal (if you catch my drift).