I'm still running Sailfish on my Nexus 5. I haven't had any issue with it as a daily driver (other than the camera).

I had bluetooth issues early on but those issues were resolved with Alpha 4. There is no way I can think of to test GPS as there is no Android compatibility (so I can't install Google Maps or Here Maps).

I don't use navigation on a daily basis and I have another device for a camera so I don't really miss running Android. My installation is also via multirom so if push came to shove and I needed navigation I can always boot over to Android.

If you have any questions feel free to ask me and I can report back here. I am currently running Alpha 6 on my Nexus 5.