Personally I haven't paid too much attention to detail of Sharpteeth sounds like you've described here, though then again I haven't watched any films for quite awhile so unfortunately I wouldn't be able to judge for myself. Plus, the lack of time to watch them also hurts that.

However though, I'm kinda surprised that your saying that they started going with cheaper, more repetitive, less intimidating Sharptooth roars/noises starting with Journey To Big Water and beyond. Like, I mean, if, despite the direct to DVD low budget sequels after the first movie, you didn't have a problem with the Sharptooth noises until the 9th movie, then I wonder what changed. Can you describe to me how the Sharptooth noises were like before the 9th movie, Mr. Clubtail? I'd like to know your thoughts on that!

And plus, whenever I watch the movies again in the future, I may pay attention to this detail more and revisit this thread to state if I agree or disagree with your rant here.