I see the New River Ospreys fairly frequently as they do some training flights to MCAS Cherry Point which is near the marina where I keep my boat. They are impressive machines as they go by....one has to admit it is a very unusual concept.
As compared to the 46's, 47's, 53's, and both Cobra's and Apache's...they have a sound print that makes them stand out from the rest. From dead ahead...they are quiet...but get very noisy as they go by.
As to the "clamming up".....it must be organizational....for when one brings up the Osprey's problems....."Mum is the word!" amongst the active duty Marines I encounter.