As far as broadcom and intel drivers. Intel is definately superior. I have both chipsets in my devices, and I've had bugs in broadcom drivers cost me hours more than once.

Absolutely this. I've had a couple of Dell Precision laptops running Ubuntu now and the one with a Broadcom WiFi chip was super frustrating. It's been a couple of years since that one but AFAIR, the connection would go down every 1-1.5 hours and you'd need to reload the relevant kernel module to get it working again. The other two have both had Intel WiFi cards and I've not seen similar issues.

If you're satisfied with 802.11n then ath9k is IMHO the best. Only driver that does not require a magic firmware blob, and has all the bufferbloat reduction features.

Yeah, but I don't know any blob-less driver for 802.11ac. Which is weird really. Why can't they make their firmware open?

For the record, Atheros is a subsidiary of Qualcomm.

Edit: wrong preposition

Yes, but Atheros was acquired by Qualcomm much later than the release of ath9k (2011 and 2008, respectively).

True.