I have the Royal Purple ATF in mine now, and I definitely hear the ticking at idle when the clutch is out. I never heard this until I switched so I know that's what caused it. I can't stand that sound, and its embarrassing when you pull up next to someone (if your in neutral and the clutch isn't depressed), or when your showing off your truck. I think on my next oil change, I'm gonna switch back over to something thicker/closer to stock. I'm not racing it really, just stoplight to stoplight fun. (or being in England, I should say from roundabout to roundabout) lol.
Be careful doing this, switching from a synthetic back to stock fluid can cause trouble. Make you you get and extra quart and flush some through it.