I have a Mac Pro 4,1, flashed to 5,1 (at home and work) and am currently running OS 10.8.5, which I will be upgrading to El Capitan. I understand that the old wifi and bluetooth versions which these machines came with will not support the upgraded functionality found in later versions of the OS, so will also be upgrading my Macs. Will third party USB dongles for Bluetooth 4 and AC 450 Wi-Fi work or will Mac OS be looking for required hardware identifiers for Apple factory hardware components and fail to recognize them? My understanding of this potential issue is limited to a vague awareness but I think third party components could require such identification written in customized kext files which would spoof the OS into thinking they were Apple components. Regarding dongles for latest wireless versions, if they work well in OS 10.8.5 does that imply that they will work well in later OS versions and make available the updated wireless features? USB 2 dongles I have purchased are: IOGEAR Bluetooth 4.0 USB Micro Adapter (GBU521) and Edimax AC450 Wi-Fi USB 802.11ac Nano-size Wireless Adapter*Full 5GHz up to 433Mbps!*. I have not installed the Wi-Fi dongle yet but it does come with drivers. The IOGEAR Bluetooth 4 dongle just works great on my Mac Pro (it comes with Windows drivers), pairing with Apple wireless input devices immediately and fixing the choppiness I was experiencing with failing Apple card. I will report on the EDIMAX Wi-Fi card when I have time to set it up. Any help in clearing this matter up would be great!