I missed this one on the original review, and it’s a subtle but welcome improvement. The so-called “Choose an Aperture Library” dialog (yeah, I dug into the manual to see what Apple called it), which you can call up by holding down the Option key on launch, or by selecting the menu File > Switch to Library > Other/New…, has seen an overhaul. Here’s the 3.0 dialog…

And here’s the new-and-improved, Aperture 3.1 dialog…

You can now quickly see — and sort by — Library Name, Version, as well as Date Modified (i.e., date last-used). That last one’s a big help if you have multiple libraries and aren’t so good at naming them or keeping them in a sensible location—this will help you find “that Library I was working on last week…”.

As always, it’s the little things… ;-)