Ray just posted his review of F5 on his site.
https://www.dcrainmaker.com/2017/03/garmin-fenix5-5s-5x-review.html
I'm missing any mention of the overlay option which is in the fenix 3 chronos beta (and I'd assume would have to be also in the newer fenix5 models).
Ray, the review does not mention Turn by Turn directions for the fenix 5/5s by directly uploading a TCX course file like you can on the 735 and f3......I could be wrong I guess and maybe Garmin has removed this capability from the 5/5s (don't have mine yet to test), but would be surprised if this was true.