I have had this prblem as well. I think Adobe should have put beta on the Community Help.
Is there any internet traffic happening during that time?
They do have a zip download for the API, but then thats not connected to Eclipse's help links.
The delay is in launching the adobe community help (ACH) or the browser. That takes 15-20 seconds. Once the ACH or browser is launched it loads the content pretty fast. There's no network activity during the delay.
It looks like it launches the help with the following command (shown in the status bar).
It works fine on OS X, but it's super slow on XP.
If I'm not mistaken that is an AIR application. It may have something to do with that and the
AIR runtime's ability to create the instance without waiting for something after Eclipse has
called it's command.
I'm sure this will be fixed in an upcoming update.
It's just as slow if I choose to open in a browser instead of in the Adobe Help AIR app.
It looks like it's a network issue. When I take the computer off the network it's fast again.