As I have mentioned on about a thousand or so occasions Aperture's ability to have a different image or image version show up on top of a stack for each and every album that you create is a huge benefit to developing an efficient work-flow. For those of you that are unfamiliar with albums and album picks you may want to take a look at the organization PDF. One of the features that I use all the time is the fact that new versions created in the context of an album automatically become the album pick. One of the minor annoyances that I have with Aperture is that new versions created with an external editor or plug-in do not share this behavior. I am sure that I could figure out why someone at Apple thought this inconsistency was a good idea if I thought about it long enough but for me it seems like an accidental mis-feature. To add insult to injury the "set album pick" function is one of those couple of things that only affect the primary in a multiple selection no matter what mode Aperture happens to be in. Several people over on the Aperture Support Forum had similar issues with this mis-feature that I suggested some ways to minimize the pain and I thought that I would share my particular workaround here as well.
In most cases I would select all of the images that I plan a new version or variation, like an aspect ratio crop and create a new album from that selection. After creating the new album I would close all the stacks, select all, and then duplicate version - hence createing both a new version for the modification and creating an album pick in one fell swoop. If you are planning on using an external editor or plugin this will not work out. If you use "edit with…" you will find that the new version is not automatically the album pick after round tripping the image to the external editor. Wow, that sucks. So here is the super secret recipie for dealing with this efficiently. Create a new album with the target images or don't it doesn't matter yet. Do your modifications to new versions with the external editor. When you are ready to go and have done all the diry work just do a quick search in the browser search box for psd or tif (the choice of formats you use for sending to the external editor) do a select all on the results and create a new album from selection. The versions that were selected will be the album picks in the newly created album. No fuss, no muss, just two keystrokes and you have your new album with all of the versions modified with an external editor at the top of the stack in that album.
I hope this helps speed things up for those of you that have been aggrivated by this speed bump.