I have a new FP3 for 3 days now. Hardware wise so far everything is awesone, no flaws.
I do have some issues with the preinstalled Stock Android 9 apps though. Google is to blame, but I’m really looking forward to an Open OS for this one to come out.
Edit: After having FP3 for some more now, I also ran into some issues. The only noteworthy one is the microphone auto-gain, which goes crazy when there is background-noises such as music. As such audio-recordings with FP3 of music or voice with music in background are almost unusable. This also affects calls when there is background noise.
I think this is a driver issue, so probably affects all FP3s but might/should be fixable with a software upgrade. see Very low quality audio recordings for details.
If your FP3 does NOT have that issue, please post that in the linked thread.