Okay, so far the new retina has been headache after headache. New issue: wifi slowdown / latency spikes. This is a 2015 MBP Retina 15" with 10.10.4. I noticed I was getting stuttering while streaming quite frequently, and sometimes my internet speed seemed to tank. After verifying this was only my laptop and not any other computer in the home (both wifi and wired computers), I did some testing. 1) If I open the Spotlight search, either by pressing the magnifying glass or using the command+space shortcut, I get a TON of kernel: IO80211ScanManager messages in Console. Saying it is initiating a scan, rescheduling a scan, etc etc. I checked this behavior on my friend's Mac Pro (trashcan) running 10.10.4, this does *not* occur in his console. I believe this scanning behavior is *supposed* to be when you click the Wifi icon, as it seems like it's scanning for other networks. Weird part: my friend's computer today didn't show these console messages even when clicking the Wifi icon. The reason this behavior is not good is that everytime these messages pop up, my latency to my router starts spiking. It's usually ~1-3ms per ping, but it starts jumping up... 70ms... 100ms... 150ms... 215ms... this keeps happening intermittently. 2) Not sure if this is related to the first issue, but I will notice my internet speed being terrible suddenly. I will verify by using speedtest.net, and my speed will be ~1-10Mbps instead of 100Mbps. Again, this is not happening on any other system I have - Mac, PC, wired, wireless, anything combo. I will also notice in terminal that my ping to my router is again, spiking as mentioned above. I believe this happens seperately to the IO80211ScanManager messages. The weird part: when I restart the computer, this issue stops entirely. Anyone have behavior like this???