In the recent newsletter, they talked about putting on a PDF.
I've found that the Mustang jacket / PDF (it has rigid foam panels inside the jacket) is fantastic! When the weather gets bad, you put on a jacket, and you also automatically put on a PDF.
I considered a harness & the inflatable PDF, but after using this for a season, I think it is the best combination. Unless if you are always dealing with 90 degree days. You won't want this jacket on if the weather is over 65 degrees.
Where I sail, a PDF is of limited use however. If you are singlehanded, then you will die of cold before someone will find you. The harness is a necessary evil - even with the PDF.