AppleScript, Finder and Mavericks

Question

I'm frustrated.
Addressing Finder in AppleScript from Mavericks is unbelievably slow. I just upgraded one of my "automation" machines (a quad-core 2.5GHz iMac with 32GB of RAM) to Mavericks from 10.8.5, and the AppleScript that has been running on it since 10.7.5 is struggling with what I would call the most basic code.
Here's the code that used to take <1 min to execute but now times-out under Mavericks:
tell application "Finder"
     with timeout of 300 seconds
          set pdfsList to every item in folder "path:to:folder:with:pdfs:" whose name extension is "pdf"
     end timeout
end tell
I'm not sure what to do here, and without figuring out a way to accomplish the same result, I'm dead in the water.
Any help/advice would be much appreciated here. I'd like to avoid reinstalling the OS, but I certainly will give that a shot if necessary.

Answer 1

You should look at the System Events.app dictionary. There are a few subtle differences: e.g. the root object for file system scripting is disk item not item, and SE prefers POSIX paths to HFS paths (where the Finder will only accept HFS paths). SE doesn't have a duplicate command, its move command is sketchy, it doesn't have any acceess to Finder labels, it lacks the 'entire contents' property of folders so that you have to do recursive folder searches for embedded objects. But even so it's much faster and more stable. Easiest thing to do when you need to access a Finder-specific function is collect HFS paths from SE and pass them to the Finder, e.g.:
tell application "System Events"
          set pdfsList to path of every item in folder "path:to:folder:with:pdfs:" whose name extension is "pdf"
end tell
tell application "Finder"
  reveal pdfsList
end tell