I have received and unpacked my F8n from B&H. I probably won't have a chance to try it out in the field until mid-September when the chamber music series I record begins its new season, but I hope to test the headphone amp and the powered connection to the FRC-8 over the next few weeks.
Anecdote: after flawless recording over three years, my F8 suddenly lost headphone amp output on June 1 (luckily after I had set up for a piano recital, and the record function worked fine for the whole time). Since I was already decided on ordering an F8n, and repair costs and express shipping would have been expensive for dealing with the remaining two recitals in June, I bought (~$60) a FiiO A3 battery powered headphone amp and fed it with the F8 sub-output, using a 1/8" male to 1/4" female cable for my Remote Audio 7506 monitoring headphones. The FiiO amp is much better than the internal headphone amp on the F8 (or any of the SD machines I have used, the 722 and 633). So I didn't have the thrill I usually get from the playback in editing (via Grace m9xx) being so much nicer than what I thought I had recorded. But I now have a very high standard to compare the new improved F8n headphone amp to.
Jeff