MacPro5,1 3.2 GHz. My last post on Dec 7 had a long list of issues and now, after finding a solution and 2 days of using the MacPro extensively, I can say with full confidence all issues are resolved.
Eureka!!!!
The culprit: RSSI. The RSSI tables were deceiving showing dBm :
0 to -60 --> good
-61 to -70 --> OK
-71 to -90 --> poor
less than -90 --> bad
There is a strong consensus that these ranges are generally true.
H o w e v e r, I found that my Apple wireless keyboard and trackpad require a higher RSSI (keep in mind these are negative numbers):
-70 shown in the 'OK' range is just not going to cut it. They will keep disconnecting and connecting endlessly.
Through more research I found the MacPro towers' metallic case severely decreases the signal strength, and on top of this there are some interference issues at play as well. Someone suggested running the Mac Pro without it's cover for stronger RSSI's, I tried it, and it worked. The RSSI went up considerably, but I'm not going to run my Mac Pro opened up all the time. Lots of forums going in depth with all of this. The most common solution is to attach an external WiFi antenna to a slot cover after drilling on it and then connecting the pigtail cable from the module to the antenna. Many success stories with this. My solution required much less effort and definitely a lot of less time and money, a 5 minute repair if you have small hands. The hardest is connecting the cable into the module. What if I told you I only spent $5.99 for this antenna http://www.osxwifi.com/review/product/list/id/20/category/3/ and I haven't had a single hickup ever since. I simply inserted the module connector of the antenna through the graphics card grill and kept it close to the motherboard all the way down to the Bluetooth module. The square antenna has a peel off adhesive to secure it... but I'm not securing it, I have it hanging as far away from the machine as possible. The changes in RSSI for the keyboard and trackpad are incredible. I'm now closer to -51 +/- 5, when it use to be in the -70's! The impact that this makes on the keyboard and trackpad's performance is just amazing. As I move the antenna closer to the tower, I can see how quickly the RSSI numbers start to come down. Handoff and all the Yosemite perks are running as expected. After many days and long hours I finally found my solution. Hope you all can find yours soon. I still believe there is a Yosemite issue since I had no problems with my wireless keyboard & trackpad with Maverick. I'm still angry at Apple for wasting my time trying to find a solution to a problem of their own creation. Good luck folks! Hope this helps.