If you do a search you will find that many users have had very good luck using it. Its not the only product that will give great results, its just one of the products that will give great results. But in answer to your question. I applied Red Max Pro to the basement doors on my 2001 MH 3 years ago and they came out looking great and still do look great.
With your MH being primarily metal, I'm assuming you've tried a good wax application? Meguires is a very good product that should give very good results. Thats all I used on my '57 Ford for years and of course it was inside all its later life, I couldn't have been happier with my results. Suggest you try a small panel for a self test and make up your own mind as to its worth. Do a similar panel close by with a good wax/polish and compare after a period of time.