Q: Battery draining super fast

If you are interested in fixing your Mac, please read below.

battery does not last more than 2-2:30hrs , before 5-6 hrs.

Please read Apps can affect Mac performance, battery runtime, temperature ....

safari slower than before ,

Please read If Safari is slow, stops responding, quits unexpectedly, or has other issues - Apple Support

Airdrop does not work as it should.

Please read Use AirDrop to send content from your Mac - Apple Support.

I have the same problem.  Just installed the new macOS and my computer is running hot, with the battery drained after only two hours instead of the previous 6 hours +  (Minimum applications open, just listening to internet radio station and Mail open)

Energy Saver options only control sleep and display times. 

I skipped the Yosemite upgrade because the reviews were bad but was finally convinced to do this one. 

I realized that there was a lot of setup running, with disk encryption taking several hours, but have restarted several times now and same problem.  Even startup takes a while, before was instantaneous. 

Can I roll back to OS X?

Sorry, I was using OS X Yosemite and skipped the El Capitan upgrade because of the reviews.

MacBook Pro (Retina, 15-inch, Early 2013)