On OS X 10.2.4 I have a demostration script to drive an application I have recently completed. While developing the script in Smile I was getting one level of performance. Once I saved the script as an AppleScript application the performance of the script dropped significantly. Brief spurts of equivalent performance to running in Smile followed by a short lull in activity. Does Smile get a higher priority than the system script runner such that its sending and receiving of events is more consistent?
I don’t know about priority but Smile probably has a larger chunk of RAM to work with. This could allow it to run scripts faster. You can fire up Process Viewer to see how much RAM is assigned to Smile vs. your script.
I don’t know if it matters in OS X but it might help to make sure that your script is frontmost.
I have also noticed that if the AppleScript applet is run using osascript that it runs much faster than double clicking it. Does this mean that the system script runner has much lower priority?