Hopeful thinking, but here's a positive story for ya:
My half ton with the lighter duty NV3500 had a mighty noisy 3rd gear when I bought it. With all the other signs of abuse after purchase, I figured that was my warning. -Decided to check fluid and couldn't reach deep enough into the fill hole to feel anything - it was practically empty and I had no clue for how long...
Topped it off with GM's Synchromesh, 3rd quieted back down, and it's been good for another 35,000 miles of partial abuse with a bigger engine and oversize tires. It might have masked another problem, but it worked noticeably better just adding fluid.
Understandably a different animal than the NV4500, but something simple to take into consideration. Guess you'll find out how "rough," it actually is when you buy it.
Happy truckin'!