Smoke damage and mold issues and electric meter monkeying/diverting (with huge fines from your utility) will knock any extra monthly you got out quickly.   

If you run into any issues needing a repair man or contractor, I have a great person I can give you his contact info.

Plus asbestos laden insulation and popcorn ceilings were an issue with many MH's.

I only needed the 203K monies to cover required "health & safety" issues.

It seems if you build it out into a proper modern small set of apartments, you can avoid any big maintenance issues for a long time, as well as making something highly desirable/and therefore priced accordingly. 

No issues on my experience.

I once had the same issue with a rodent that died in the attic, and I called multiple pest control companies and they all told me the same thing - that all they could do was charge me to go up there and look for it in hopes of finding/removing it.

No major foundation issues.

Sometimes there are errors in public records (example: inaccuracy on a deed, unknown liens, forged documents, boundary issues etc).

I changed a water heater, huge leak in one of the units, electrical issues, and I even had to dig a 3 foot hole under the house and personally fix a pipe.