Upgraded Nexus 5 to Android 6 = more space!

Marshmallow is available for update on my Nexus 5 today finally. The upgrade was smooth.  Download took less than 30 min and less than an hour for the upgrade with more than 20 minutes spent on processing the apps after the device was restarted.

It has been running for around an hour and all seem fine too. Some initial observations I have,

• The UI is very much similar to Android 5. This is good and I don't have have to adapt to something else. 
• After the upgrade, free storage space has increased almost 3GB?! Surprise and I wonder where they come from.  And I don't seem to have lost any file.
• The previous EMail icon was flagged suggestion me to download the separate Google Email app (I was using GMail all the way). I declined and continue to use GMail. This is my second upgrade mystery and no know what is the reason to have 2 EMail app from Google.

While I was installing, was reading more about new features on the web and below what I would suggest for other to get more information. 

http://www.cnet.com/products/google-android-6-0-marshmallow/
https://www.android.com

Among all changes, longer battery life and finer security control are eye-catching for me. Too early for any comment now and time will prove whether they are useful. Will comment on that later.

P.S. I have replaced my battery recently and that really fixes my battery problem after using the device for almost 2 years. Highly recommended for others who have the same problem.  The installation is simple and just need some patience.