I can recommend it for everyone who doesn't need ac wifi and does not want to mess with MP's Wifi and BT internal cards. (and a later update added 3/2/2015) Update on the CAT/ Bluetooth 4 USB dongle/Continuity front. The only thing I might have overlooked is that all the devices have to have BT turned on for Continuity to work :).
I was browsing in Safari on my Mac Pro with the USB Bluetooth 4 (BT 'on') and noticed that I have got a Safari icon on my i Phone's lock screen! Silly me, forgot to turn the i Phone's BT on at one point :) Anyway this little thing gives me all the features I want from yosemity.
(10.9.2 currently.) In OS X 10.9.2, the native Mac OS X Broadcom drivers do not reach 200mbps with an identical router setup. (My 2007 i Mac 802.11n (5GHz) link rates are better than that.) Have you tried using OS X Wi Fi Diagnostics tools?
(My work machine has 10.6.8 so no Wi Fi diagnostics utility, but option click on Wifi icon shows stats (channel, RSSI, Transmit rates (varies).
I dont really need ac in this tower as I use ethernet for communication.
Thanks again for your site, been your reader for more than 10 years now.
(added 4/22/2015) "802.11AC Mac adapters - Last Update on Asus PCE-AC68 PCIe card This is my last update on this card because my Mac Pro 3.1 (still performing very well) goes out of my house and is replaced by a nice i Mac.
For some reason when I did the p-ram zap multiple times in a row, everything cleared up.
Best wishes Grzegorz W."(added 2/24/2015, updated 3/2/2015) "GMYLE BT4 USB dongle used with 10.10.2 on my Mac Pro 5.1 Hello again, I promised to let you know if my BT4 dongle works. I can receive SMSes from my iphone in imessages, BT low power is supported according to system profiler, I can also receive calls from the iphone, but haven't tested it yet. When visiting a webpage on other devices I receive notification on all the others that a webpage has been visited on iphone or mac.
It works on the mac pro, but after visiting a webpage on the mac pro it does not let other devices know that an event took place.
Card from the 13" non-retina mid 2012 Mac Book Pro - CM94331PCIEBT4CAX installed in my early 2011 Mac Book Pro 17".
Works like a charm in OS X 10.10.2 with continuity.