Please tell me how this differs from the construction of any other home, manufactured, stick-built, or modular. Barrier wrap is not the Thing To Do anymore, as it caused houses to be too airtight, leading to problems with mold and mildew from the moisture unable to escape the house. We all breathe out several pints of water a day. Add in steam from showers and cooking liquids and you have a lot of moisture buildup internally. I have seen stick-built houses only 5 years with mold problems ultimately caused by the barrier wrap.

You have 2x6 external framing, which older stick-built houses do not have. You have OSB because it is actually stronger than plywood. If your house is like mine there isn't a level window or plumb wall in the entire place - but you won't find those things in ANY house today. Construction is crappy because they are all about speed, not quality, and it's not limited to manufactured homes by any means. Tour some model homes with a critical eye and see what I mean.

Hmm I hate to say it but OSB is NOT stronger than plywood! It is cheaper than plywood for a reason. Unless you are buying a cheaper grade plywood, OSB is NOT stronger. There have been MANY tests that proved this VERY point! Believe me, I am in hurricane country. I will be building with plywood. I have seen OSB disasters, mainly in the trailer house that we purchased and redid floors with it. I would NEVER use that CRAP again!

You are correct about plywood being stronger but not necessarily if it is on 3 ply and not 5 ply