Hello,
I too have this model. Everything worked as you described above. I will replace my wifi adapter with a Broadcom. Only issue is the sound.
I found this link in another thread where is seems someone has the same audio on an ASUS.
Here is the link in the forum: https://osxlatitude.com/index.php?/topic/5974-mavericks-1091-hm87-iris-5100-asus-ux301la/
If I knew how to add the driver to the extras I would. Any help that someone can provide is appreciated.