Severe Bluetooth Connectivity Issues - OS X Yosemite+El Capitan Ever since Yosemite, Bluetooth connectivity on my very modern MBP w/Retina has been absolute garbage. My workspace includes the Apple wireless keyboard + Magic Trackpad, and I usually am also using Bluetooth headphones (specifically these August EP650's which have been fantastic when paired with other devices/Macs). 

The problems begin with pairing these devices to the Mac, which usually is around a half hour process of the Mac not finding the devices/refusing to connect. Once connected, it is only a matter of minutes before the devices start to lag out. In the case of the Trackpad, I am referring to the fact that it will be jumpy when trying to scroll, and won't register clicks/taps. The audio on the headphones is even worse, making music or podcasts virtually unlistenable with the constant skips and lag. The keyboard tends to be the most stable of the bunch, but occasionally I will type out a sentence and not see it display on the screen, only to then see the entire thing spell out rapidly a second or two later.

I have filed an issue with Apple and they have been absolutely useless in resolving this. I send them Bluetooth Diagnostic Reports on about a weekly basis, but they have not responded in over 4 months. This is extremely frustrating as this never used to be an issue before Yosemite+El Capitan. I have wasted numerous hours trying to debug it, such as the following:  


Holding SHIFT+ALT and clicking the Bluetooth icon in the top bar, which reveals the debug menu, and then selecting DEBUG>Reset The Bluetooth Module. This usually results in about a 5 minute 'grace period' before the issues arise again
From the same debug menu, I've tried "Factory Resetting All Apple Devices" which is also useless (and also a pain because I then have to re-pair which takes forever).
Disabling the Handoff feature (the one useful feature added in Yosemite). This was recommended around 4 months ago when Apple was responding to my bug report.
Resetting the SMC &amp; PRAM - at first I thought this worked but alas no dice.
I've tried some other tips that involve setting some BluetoothAudioAgent properties via the terminal and they have (so far) not solved the issue.


I thought that El Capitan would resolve this but I was wrong. It in fact got noticeably worse. It is a work machine and the LAN/equipment technician guy here can't figure it out, and because it's not my machine I'm not able to just take it in to Apple (plus I'm not going to pay to repair a machine that isn't mine). On top of that, I don't think this is a repairable hardware issue, because the Bluetooth was working so smoothly before Yosemite.

Any suggestions you might have are greatly appreciated, I am at my wits end.
There is a lot of pain, but you have all the tools you need to isolate the issue:


Install 10.9 on an external drive. 
Install 10.10 on an external drive. 
Install 10.11 on an external drive. 


It is important to get a totally clean install of the three items above. You can then use a notebook to write down the exact times and OS when Bluetooth if flakey. If it's really the software drivers, you will have statistical evidence of that after 10 to 20 data points. The down side of this, troubleshooting like this is expensive time-wise and we don't ever get that time back. 

I hate to throw hardware at an issue, but wired devices or upgrading to Apple's newer hardware have helped in areas where I had clients with noisy 2.4 Ghz environments. The new hardware is Bluetooth low energy and superior to the old devices in terms of resilience and the amount of time to link back up when they inevitably disconnect. As a bonus, they work over USB in the case of the new "magic" keyboard and trackpad devices. Other third party options also exist with transmitters that don't depend on the Bluetooth stack. 

Make a "budget" for your troubleshooting effort and buy a solution that you could return if it doesn't solve our issue. Since it happens so often, you should be able to know with Apple’s 14 day return window if the new hardware will solve your pain. (And if it's cheaper once you put a $ value on your time to troubleshoot the issue further.)


Reset Mac OS X Bluetooth service?


Also, this answer to the above question has some critical information on using the debug menu to factory reset things. You might try each of these (writing down what you do and when - leaving a little time between each option) to see if a reset helps. The logging and diagnostic report will also help if you need to engage Apple support to troubleshoot the issue. Sometimes looking at the logs has helped me identify a failure.

Best of luck - I'm curious what you find out.