S!
You can remove the Cougar throttle detents (the things that go
clunck)
.. There are instructions in Cougar World site if I remember correctly.
To answer your question:
The Warthog throttle is quiet. Well, depends on how violently you use the switches or the Idle detent. But the throttle lever itself moves smooth and quiet.
My Cougar stick gave out a month ago after serving for 5 years (the cast aluminum inner workings just gave out). So I bought the Warthog(stick+throttle) ... and after getting it I noticed that it would have been available as stick only for 100€ cheaper ("damn")
.. I personally like the Cougar throttle better and still use it.
But the stick is awesome. It moves so fluidly, and the spring isn't so powerfull so my hand won't get as tired on long flights
.. The Cougar stick had a very clear center in its axis where the stick would get slightly stuck. Warthog doesn't have it, it goes very fluidly in every position. This makes aiming much easier.