I've been using mine for 3 days and FINALLY Apple has figured out how to do a decent display, I've never been thrilled with it in the past, even on the Pros. I have nothing negative to say about this phone. The battery is fine, with or without the battery pack and I've been using the speaker without any issues. In fact it's so adequate I don't see what all the fuss was about on that, unless it's landscape users which I hate on any device, I always use portrait. I haven't really used the camera so I can't comment on that.
I have also been using it caseless and so far without a screen protector to test it out, but eventually I will probably install one.