Unlike others here that did an in-place update, I did a cache wipe prior to updating, I updated, then I did a factory reset. Years of rooting and hacking kernels taught me to always start with a clean slate. Plus, for me, it's great to get rid of baggage that inevitably collects in the corners of the OS, so to speak.
Here's what I've noticed so far, some of which I posted earlier.
- Google Gesture Search is broken in 6.0.1. If you are not familiar with this app, check it out (once it gets fixed!). It's been a mainstay of my phone for years. You'll never go back to using the old Contacts app again. Well, it installs, works briefly, but then is stops working and throws the error message indicating so. Bummer. Hey Google - fix it!
- I've gotten fingerprints to work as my security mode in most cases. This took some doing, as in 6.0.1 I think there are new interdependencies between security functions - just a guess. I needed to repeatedly revisit all of the fingerprint settings (there are a few of them) and set/reset. Then, automagically, my phone started working they way it did with Lollipop. But, I absolutely can't figure out how to have fingerprints to be the way to unlock my phone after a restart. It will only unlock with my password.
- Fingerprints are faster and more accurate. What an improvement!
- I can't seem to get weather back on my lockscreen. Yes, I have the weather app enabled for the lockscreen - it just doesn't display.
- Doze works freeegin' great. Thanks Google. My N5 has gone from very good to amazing with Doze.
- I've left all of the bloatware in place and will keep it there a little longer. Then I will use Package Disabler Pro to get rid of it all. Just didn't want too many variables during the honeymoon phase with 6.0.1
- I can't get into UI Tuner. Tried everything I can find - no dice. I just can't get that little gear to spin. Tried swiping down twice (which never works for me - the gear gets replaced), turned on Dev Options, tried from within Dev Options, and have held that freegin' gear for over a minute one time. No workey.
- The update is perfectly stable so far, looks great and with animations cut back a bit in Dev Options, very very snappy.
- Can't for the life of me find the "Reader" mode in the new Sammy Internet 4.0 browser. I installed Adblock Fast and this browser is the sh*t. In my brief experience with it, it totally smokes Chrome - and no ads. Amazing.
If anyone has insights into any of this, please chime in.