Aperture, PhotoStream, and "(Imported Keyword)"
I love keywords. Use them all the time. And spent considerable time getting my keyword hierarchy the way I want it. Last week I noticed my tidy keywording hierarchy was, shall I say, tainted. Keywords I know I'd used were showing up at the top level of my hierarchy. The first couple of times I figured it was a glitch with the keyword buttons I'd set up, so I rebuilt them. But out of place keywords kept appearing. So I locked my keywords. Then a few days later I noticed a strange "(Imported Keyword)" entry at the top of my keyword hierarchy.
After plenty of experimentation, I traced this down to (what I consider) a bug with Aperture and PhotoStream. I use PhotoStream is a very simplistic way - to share photos I've recently worked on with the family iPad. What evidently happens is that keywords for the just-streamed photo are imported back into Aperture. No merging happens. While I can see this as potentially useful for some workflows, it's sheer annoyance to my simple use case.
The workaround for me is to keep my keywords locked (not a big issue, they don't change much) and ignore "(Imported Keyword)". Why I think this is a bug is that these keywords don't seem to provide any value. While chasing down the problem, I used a simple keyword filter in the Photos album - show me all versions with "(Imported Keyword)" set. Also tried specifying a specific keyword such as "Boy (Imported Keyword)". The filtered searches were always empty.
As I said, I'm sure there's a workflow where importing keywords can be useful. But at present, there's little use to imported keywords. Can't filter or search for them and they can quickly muck up an unlocked keyword hierarchy. I think the gang in Cupertino needs to give this particular feature more thought - and at least provide an option to turn it off.