Downloaded and installed the update. My criticisms :
1. Darn Darn and Darn ... the "quick unlock" (you enter correct PIN to unlock w/o pressing OK button) is MISSING. Grrrr...
2. In CM12, I had assigned long press of 'on screen Nav Home Key' to Screen-Off or go to search. GONE in CM13. Grrrrrrrrrrr.
This was super cool. With 'double tap to wake screen ' and this, I mainly used Power ON button for getting Screenshot :-) Now Nav keys are disabled and the 'three capacitive navigation' keys have been enabled back. I've assigned double tap on Home Key to "screen off". Basically no need to use Power ON button again. About Marshmallow Goodness :
When you press and hold onto something in Browser, a 'Copy - share - Select All - Web Search - Translate' ribbon appears. Press Share, and surprise surprise, it shows your frequent Whatsapp contacts in the top row followed by Whatsapp, Messaging, Google+, Yahoo Mail, Gmail, Send by LAN (what's this?), Bluetooth, Hike, Vibe, and compatible Apps like Calendar, Evernote, Keep (didn't know this is in my phone) etc.
The Share option doesn't appear in the Ribbon, say when I chose a word in this editing window. That's cool.
The toggle switched can be edited and rearranged just by pulling down from Status Bar itself, instead of having to enter setting. And a Toggle is now available against "BT, WiFi, Data" at first entry into Settings. Earlier I had to enter one level deep. I remember this was available in my Moto Atrix 2 in the 2012 itself. V...e...r...y slow CM team.
About performance improvements - No idea.
About battery life - No idea.
Look at the date of 'Android Security Patch Level' at the bottom of Pic. It is 01-May-2016. They rolled the OTA Four days ahead of their plan ? Good project execution guys. Kudos.
My Wife's Asus Zenfone 5 is still on Android 4.4. ASUuuuuuuS, learn from CM team. Off Topic - Quick Review of Mi Battery Bank :
Bought a Mi 20,000 mAh Power Bank in the Flash Sale from Mi App on 27th ; for a friend. It came today, with some 20% charge. It got empty after charging my half charged phone. Length and Breath wise, it is little smaller than my Phone and thickness could be around an inch. Weighs heavy, but 20,000 mAh is HEAVY. Cost was 1699/- Cool. Here in this Photo, it is next to my Daughter's Vibe P1m and my own Mi 5,000mAh Power Bank. Just for info guys.