I can't speak for all trailers the military disposed of, just know a couple of ex diggers who I worked with that have them for personal use. I know they take a hiding, but they are built for it, end of the day it's still buyer beware, and you do your homework.
If your not confident in Army gear and you don't like RAAF trailers ( if you can get them), the solution is simple. Don't buy one, save up your money and spend a little more on something decent/ new.
This comes down also to 2 simple rules:
1. Buyer beware ( do your homework)
2. You get what you pay for.
Cheers
Campfire
If your not sure,